I Run the Most thriving SPS Tank on 0 P and 0 N

[sixty_reefer]

Yes - a brick has a Redfield ratio as well - but - no one calculates it.... The Redfield ratio is N to P of 16:1. This says nothing about the amounts of N and P - i.e. the Ratio of N to P in a tank with N 0.00016 and P 0.00001 is the same as the tank with the N being 160 and the P being 1. What is the benefit?

I tough we were going to have a constructive discussion? The ratio 16:1 says for each 1 part of phosphorus being used 16 parts of nitrogen are also used. Hence the question what’s the brick consuming? Isn’t there a reason no one bothered to calculate it [emoji57]

 

[MnFish1]

I tough we were going to have a constructive discussion? The ratio 16:1 says for each 1 part of phosphorus being used 16 parts of nitrogen are also used. Hence the question what’s the brick consuming? Isn’t there a reason no one bothered to calculate it [emoji57]

We are - I was responding to another post where you suggested that 'even humans have a Redfield ratio'. No one calculates that ratio either (just like the brick). I didnt get the point of why you can calculate the ratio of N and P in a human means anything with regards to reef aquaria - thats all

 

[MnFish1]

The ratio 16:1 says for each 1 part of phosphorus being used 16 parts of nitrogen are also used.

I dont think this is what the ratio 'says'. The ratio only shows the ratio of N to P at a given point for a given group of phytoplankton. It does say anything about what's being consumed (on its own) - its far more complex than that - for example if N is low - the organism may be able conserve it, etc etc etc.

 

[Terrp]

This has been an interesting discussion. Boiling it all down, would the following be good, practical insights for a newbie?

1. For these purposes, a newbie would be someone who is new to the hobby, doesn’t have a lot of technical background regarding water parameters, doesn’t have a lot of large corals to suck up N and P and likely doesn’t have the skill or time for advanced reef keeping methods or corrective actions.
2. There are apparently successful tanks with high N & P, those with zero or close to zero N and P, and plenty in between.
3. A good target for the newbie would be to seek low but detectable N & P for the following reasons:
   1. Zero N & P could lead to dinos.
   2. Zero detectable N & P could starve corals or at least limit growth.
   3. Having detectable N &P ensures that your nutrient export isn’t removing nutrients faster than your corals so that your corals always have at least as much as they need.
   4. Avoiding high N & P helps to avoid nuisance algae outbreaks like green hair algae (GHA).

Some practical advice on how to safely maintain low but detectable N & P while minimizing the possibility of nuisance algae outbreaks would seem to be a useful extension of the guidance for newbies. I didn’t see a lot of that above, so here are some initial thoughts as a starting point (based on my own experiences and research over the years):

1. Use algae turf scrubbers (ATS) or macro algae like Chaeto in refugiums, rather than media like GFO, since media may absorb nutrients too quickly, thus outcompeting corals for nutrients.
   1. I’ve tried lots of scrubbers and refugium setups. I personally find the relatively new RAIN scrubbers from Santa Monica Filtration to be the easiest and most effective. I found lighted Chaeto refugiums can be hard to establish in new tanks and can make sump maintenance a pain while potentially growing GHA along with the Chaeto if not well maintained.
2. If N & P are undetectable, the best ways to obtain slightly higher nutrient levels would be as follows:
   1. Decrease or eliminate the use of media like GFO.
   2. Decrease light timing for ATS/refugium.
   3. Increase feeding.
   4. (As a last resort) Dose NeoPhos and/or NeoNitro, but in small amounts throughout the day rather than large amounts periodically. An automated doser would be ideal.
3. Begin growing coralline algae immediately and as quickly as possible to outcompete nuisance algae for space on the rocks.
   1. Use Coralline In A Bottle to seed the tank faster.
   2. Use mostly actinic/blue spectrum lighting until coralline is established since that’s better for coralline while nuisance algae prefers white and red spectrums.
   3. Keep pH close to 8.3. A CO2 scrubber may be needed for some setups.
   4. Keep temp 78-82.
4. Add a clean-up crew (CUC) to eat detritus and algae. My favorites:
   1. Snails (especially those that can right themselves or breed).
   2. Hermits (but only red-leg and blue leg, and not too many).
   3. Emerald crabs.
   4. Shrimp (cleaner or fire).
   5. Bristleworms, copepods and amphipods.
5. Eliminate detritus build-up. Options include:
   1. Mechanical filtration like sponge, filter socks or filter rollers. My new favorite by a mile is the ClariSea roller.
   2. Blow off rocks during water changes. If you have a filter roller, you could also do without a water change.
   3. Periodically clean pipes & sump.
   4. Use good circulation to avoid dead spots.
   5. Dr. Tim’s Waste Away.
6. If you still get GHA or other nuisance algae, some of the best steps are as follows:
   1. First, remove as much as possible from the tank. Removing the rock from the tank and scrubbing in tank water during a water change is ideal, but you’ll have to scrub in place inside the tank while siphoning away the algae during water change if aquascaping or corals don’t allow removing the rocks.
   2. Second, use a treatment based on bacteria (not miracle chemicals) to fight back the remaining algae. Vibrant Liquid Aquarium Cleaner for Reef Tanks and Dr. Tim’s Recipe (includes several days of Refresh & Waste Away) are apparently good options, though newbies should research carefully before trying any treatment.
   3. Keep N & P low and the red/white spectrum lighting low until coralline thrives instead of nuisance algae.
   4. A UV sterilizer could be helpful to kill floating algae spores, though it probably isn’t necessary in the average size newbie tank if everything else above is in check.

Any corrections or updates that might help a newbie?

 

[sixty_reefer]

This has been an interesting discussion. Boiling it all down, would the following be good, practical insights for a newbie?

1. For these purposes, a newbie would be someone who is new to the hobby, doesn’t have a lot of technical background regarding water parameters, doesn’t have a lot of large corals to suck up N and P and likely doesn’t have the skill or time for advanced reef keeping methods or corrective actions.
2. There are apparently successful tanks with high N & P, those with zero or close to zero N and P, and plenty in between.
3. A good target for the newbie would be to seek low but detectable N & P for the following reasons:
   1. Zero N & P could lead to dinos.
   2. Zero detectable N & P could starve corals or at least limit growth.
   3. Having detectable N &P ensures that your nutrient export isn’t removing nutrients faster than your corals so that your corals always have at least as much as they need.
   4. Avoiding high N & P helps to avoid nuisance algae outbreaks like green hair algae (GHA).

Some practical advice on how to safely maintain low but detectable N & P while minimizing the possibility of nuisance algae outbreaks would seem to be a useful extension of the guidance for newbies. I didn’t see a lot of that above, so here are some initial thoughts as a starting point (based on my own experiences and research over the years):

1. Use algae turf scrubbers (ATS) or macro algae like Chaeto in refugiums, rather than media like GFO, since media may absorb nutrients too quickly, thus outcompeting corals for nutrients.
   1. I’ve tried lots of scrubbers and refugium setups. I personally find the relatively new RAIN scrubbers from Santa Monica Filtration to be the easiest and most effective. I found lighted Chaeto refugiums can be hard to establish in new tanks and can make sump maintenance a pain while potentially growing GHA along with the Chaeto if not well maintained.
2. If N & P are undetectable, the best ways to obtain slightly higher nutrient levels would be as follows:
   1. Decrease or eliminate the use of media like GFO.
   2. Decrease light timing for ATS/refugium.
   3. Increase feeding.
   4. (As a last resort) Dose NeoPhos and/or NeoNitro, but in small amounts throughout the day rather than large amounts periodically. An automated doser would be ideal.
3. Begin growing coralline algae immediately and as quickly as possible to outcompete nuisance algae for space on the rocks.
   1. Use Coralline In A Bottle to seed the tank faster.
   2. Use mostly actinic/blue spectrum lighting until coralline is established since that’s better for coralline while nuisance algae prefers white and red spectrums.
   3. Keep pH close to 8.3. A CO2 scrubber may be needed for some setups.
   4. Keep temp 78-82.
4. Add a clean-up crew (CUC) to eat detritus and algae. My favorites:
   1. Snails (especially those that can right themselves or breed).
   2. Hermits (but only red-leg and blue leg, and not too many).
   3. Emerald crabs.
   4. Shrimp (cleaner or fire).
   5. Bristleworms, copepods and amphipods.
5. Eliminate detritus build-up. Options include:
   1. Mechanical filtration like sponge, filter socks or filter rollers. My new favorite by a mile is the ClariSea roller.
   2. Blow off rocks during water changes. If you have a filter roller, you could also do without a water change.
   3. Periodically clean pipes & sump.
   4. Use good circulation to avoid dead spots.
   5. Dr. Tim’s Waste Away.
6. If you still get GHA or other nuisance algae, some of the best steps are as follows:
   1. First, remove as much as possible from the tank. Removing the rock from the tank and scrubbing in tank water during a water change is ideal, but you’ll have to scrub in place inside the tank while siphoning away the algae during water change if aquascaping or corals don’t allow removing the rocks.
   2. Second, use a treatment based on bacteria (not miracle chemicals) to fight back the remaining algae. Vibrant Liquid Aquarium Cleaner for Reef Tanks and Dr. Tim’s Recipe (includes several days of Refresh & Waste Away) are apparently good options, though newbies should research carefully before trying any treatment.
   3. Keep N & P low and the red/white spectrum lighting low until coralline thrives instead of nuisance algae.
   4. A UV sterilizer could be helpful to kill floating algae spores, though it probably isn’t necessary in the average size newbie tank if everything else above is in check.

Any corrections or updates that might help a newbie?

Thanks for taking the time, this has to be the best and more complete advice I’ve seen, what you just wrote should become a sticky somewhere in this forum many new hobbiest would benefit from such advice.

 

[Reef_Hobbyist]

My opinion...

This is like trying to tell someone the number of calories they need to stay at the same weight.... and you don't even get to know anything about the person. Best you could do is probably give them some general guidelines but it certainly won't be a number.

Test kits are reading unused N and P. So if those numbers are rising then there is leftover after use and export. If they are declining there is a deficit. If they are stable at a specific number, it just means that the use and export is matching the incoming supply.

The problem comes in when they are reading 0. It could be perfectly fine and stable at zero or it could be in a deficit (no way to measure below 0 and find out for sure).

Therefore, people who have something higher than zero, and it stays consistent at that number, seem to have good results with their systems and encourage others to do the same. They will always know if they begin to go into a deficit (their numbers have room to go down) and they have more wiggle room to absorb a deficit if it happens.

Zero means either perfectly fine or starving.... :-0

 

[Marie7]

Said no one ever....

I’ve noticed that most of the threads lately on here are all related to none of the above be present in the tank. I could go scientific on you but that’s not the goal here. 0 nutrients and 0 phosphate is BAD and it will cause most of the issues in your tank. Let’s not forget that there’s a big difference between running a low nutrient tank and a 0 nutrient tank.

Is always hard to repeat yourself so let’s make this a informative thread on running 0 nutrient tanks, share your opinions and information.

Hummmm i honestly try to dose my tank with NoPox and cause mote damage than anything else, my corals start to shrink and dry or die, i lost a lot of corals because of this chemicals no matter how we look at this it is chemicals that makes any tank become unbalance, i’ m runing a low P&N and it is starting to pick up again netherless to say that I never was able to get the N&P out of my tank completely, after a few days and weeks I decide to give up and accept that I will always will have an amount of N&P on my tank, I change my water periodically , add one of those porous stones that end up disintegrating on my sump and no change until i stop dozing my tank, so with that being said i would like to know how people end up with 0-P and 0-N .... i buy my water at the reef store and my set up its simple: 92 gallons, sump with a protein skimmer and periodically I add a bag of charcoal and a bag of phos-zord what ever its call any ways, will some one really could have a 0000 tank?

 

[Daniel@R2R]

This has been an interesting discussion. Boiling it all down, would the following be good, practical insights for a newbie?

1. For these purposes, a newbie would be someone who is new to the hobby, doesn’t have a lot of technical background regarding water parameters, doesn’t have a lot of large corals to suck up N and P and likely doesn’t have the skill or time for advanced reef keeping methods or corrective actions.
2. There are apparently successful tanks with high N & P, those with zero or close to zero N and P, and plenty in between.
3. A good target for the newbie would be to seek low but detectable N & P for the following reasons:
   1. Zero N & P could lead to dinos.
   2. Zero detectable N & P could starve corals or at least limit growth.
   3. Having detectable N &P ensures that your nutrient export isn’t removing nutrients faster than your corals so that your corals always have at least as much as they need.
   4. Avoiding high N & P helps to avoid nuisance algae outbreaks like green hair algae (GHA).

Some practical advice on how to safely maintain low but detectable N & P while minimizing the possibility of nuisance algae outbreaks would seem to be a useful extension of the guidance for newbies. I didn’t see a lot of that above, so here are some initial thoughts as a starting point (based on my own experiences and research over the years):

1. Use algae turf scrubbers (ATS) or macro algae like Chaeto in refugiums, rather than media like GFO, since media may absorb nutrients too quickly, thus outcompeting corals for nutrients.
   1. I’ve tried lots of scrubbers and refugium setups. I personally find the relatively new RAIN scrubbers from Santa Monica Filtration to be the easiest and most effective. I found lighted Chaeto refugiums can be hard to establish in new tanks and can make sump maintenance a pain while potentially growing GHA along with the Chaeto if not well maintained.
2. If N & P are undetectable, the best ways to obtain slightly higher nutrient levels would be as follows:
   1. Decrease or eliminate the use of media like GFO.
   2. Decrease light timing for ATS/refugium.
   3. Increase feeding.
   4. (As a last resort) Dose NeoPhos and/or NeoNitro, but in small amounts throughout the day rather than large amounts periodically. An automated doser would be ideal.
3. Begin growing coralline algae immediately and as quickly as possible to outcompete nuisance algae for space on the rocks.
   1. Use Coralline In A Bottle to seed the tank faster.
   2. Use mostly actinic/blue spectrum lighting until coralline is established since that’s better for coralline while nuisance algae prefers white and red spectrums.
   3. Keep pH close to 8.3. A CO2 scrubber may be needed for some setups.
   4. Keep temp 78-82.
4. Add a clean-up crew (CUC) to eat detritus and algae. My favorites:
   1. Snails (especially those that can right themselves or breed).
   2. Hermits (but only red-leg and blue leg, and not too many).
   3. Emerald crabs.
   4. Shrimp (cleaner or fire).
   5. Bristleworms, copepods and amphipods.
5. Eliminate detritus build-up. Options include:
   1. Mechanical filtration like sponge, filter socks or filter rollers. My new favorite by a mile is the ClariSea roller.
   2. Blow off rocks during water changes. If you have a filter roller, you could also do without a water change.
   3. Periodically clean pipes & sump.
   4. Use good circulation to avoid dead spots.
   5. Dr. Tim’s Waste Away.
6. If you still get GHA or other nuisance algae, some of the best steps are as follows:
   1. First, remove as much as possible from the tank. Removing the rock from the tank and scrubbing in tank water during a water change is ideal, but you’ll have to scrub in place inside the tank while siphoning away the algae during water change if aquascaping or corals don’t allow removing the rocks.
   2. Second, use a treatment based on bacteria (not miracle chemicals) to fight back the remaining algae. Vibrant Liquid Aquarium Cleaner for Reef Tanks and Dr. Tim’s Recipe (includes several days of Refresh & Waste Away) are apparently good options, though newbies should research carefully before trying any treatment.
   3. Keep N & P low and the red/white spectrum lighting low until coralline thrives instead of nuisance algae.
   4. A UV sterilizer could be helpful to kill floating algae spores, though it probably isn’t necessary in the average size newbie tank if everything else above is in check.

Any corrections or updates that might help a newbie?

Excellent summary!

 

[Terrp]

Excellent summary!

Thanks! I see that I left out some other helpful tips (i.e., use a good properly sized skimmer, get tangs or other grazing fish as part of the CUC, keep the sand bed clean or go bare bottom, shoot for stability in N, P and all other water parameters), but hopefully that can serve as a good starting point!

 

[Pyrosteve]

This has been an interesting discussion. Boiling it all down, would the following be good, practical insights for a newbie?

1. For these purposes, a newbie would be someone who is new to the hobby, doesn’t have a lot of technical background regarding water parameters, doesn’t have a lot of large corals to suck up N and P and likely doesn’t have the skill or time for advanced reef keeping methods or corrective actions.
2. There are apparently successful tanks with high N & P, those with zero or close to zero N and P, and plenty in between.
3. A good target for the newbie would be to seek low but detectable N & P for the following reasons:
   1. Zero N & P could lead to dinos.
   2. Zero detectable N & P could starve corals or at least limit growth.
   3. Having detectable N &P ensures that your nutrient export isn’t removing nutrients faster than your corals so that your corals always have at least as much as they need.
   4. Avoiding high N & P helps to avoid nuisance algae outbreaks like green hair algae (GHA).

Some practical advice on how to safely maintain low but detectable N & P while minimizing the possibility of nuisance algae outbreaks would seem to be a useful extension of the guidance for newbies. I didn’t see a lot of that above, so here are some initial thoughts as a starting point (based on my own experiences and research over the years):

1. Use algae turf scrubbers (ATS) or macro algae like Chaeto in refugiums, rather than media like GFO, since media may absorb nutrients too quickly, thus outcompeting corals for nutrients.
   1. I’ve tried lots of scrubbers and refugium setups. I personally find the relatively new RAIN scrubbers from Santa Monica Filtration to be the easiest and most effective. I found lighted Chaeto refugiums can be hard to establish in new tanks and can make sump maintenance a pain while potentially growing GHA along with the Chaeto if not well maintained.
2. If N & P are undetectable, the best ways to obtain slightly higher nutrient levels would be as follows:
   1. Decrease or eliminate the use of media like GFO.
   2. Decrease light timing for ATS/refugium.
   3. Increase feeding.
   4. (As a last resort) Dose NeoPhos and/or NeoNitro, but in small amounts throughout the day rather than large amounts periodically. An automated doser would be ideal.
3. Begin growing coralline algae immediately and as quickly as possible to outcompete nuisance algae for space on the rocks.
   1. Use Coralline In A Bottle to seed the tank faster.
   2. Use mostly actinic/blue spectrum lighting until coralline is established since that’s better for coralline while nuisance algae prefers white and red spectrums.
   3. Keep pH close to 8.3. A CO2 scrubber may be needed for some setups.
   4. Keep temp 78-82.
4. Add a clean-up crew (CUC) to eat detritus and algae. My favorites:
   1. Snails (especially those that can right themselves or breed).
   2. Hermits (but only red-leg and blue leg, and not too many).
   3. Emerald crabs.
   4. Shrimp (cleaner or fire).
   5. Bristleworms, copepods and amphipods.
5. Eliminate detritus build-up. Options include:
   1. Mechanical filtration like sponge, filter socks or filter rollers. My new favorite by a mile is the ClariSea roller.
   2. Blow off rocks during water changes. If you have a filter roller, you could also do without a water change.
   3. Periodically clean pipes & sump.
   4. Use good circulation to avoid dead spots.
   5. Dr. Tim’s Waste Away.
6. If you still get GHA or other nuisance algae, some of the best steps are as follows:
   1. First, remove as much as possible from the tank. Removing the rock from the tank and scrubbing in tank water during a water change is ideal, but you’ll have to scrub in place inside the tank while siphoning away the algae during water change if aquascaping or corals don’t allow removing the rocks.
   2. Second, use a treatment based on bacteria (not miracle chemicals) to fight back the remaining algae. Vibrant Liquid Aquarium Cleaner for Reef Tanks and Dr. Tim’s Recipe (includes several days of Refresh & Waste Away) are apparently good options, though newbies should research carefully before trying any treatment.
   3. Keep N & P low and the red/white spectrum lighting low until coralline thrives instead of nuisance algae.
   4. A UV sterilizer could be helpful to kill floating algae spores, though it probably isn’t necessary in the average size newbie tank if everything else above is in check.

Any corrections or updates that might help a newbie?

This 100%. I think for a new reefer like me this video from BRS should be required...




That said from all the research I've done I think that NEAR undetectable is the way to go. I read a bunch of build threads and it seemed to me the horror stories were mostly from GHA and dinos. One is nutrients too high the other too low. I also read some people using a "Heavy In - Heavy Out" method. Heavy feeding and heavy exporting. To me this seemed logical. Feeding heavy ensures there's always nutrients in the tank to keep the dinos away and when it breaks down it's quickly exported by skimming wet, a refugium and a GFO reactor, keeping numbers near zero. This seems to be working well for me so far. No dectable Nitrates or Phosphates. No serious algea problem and I'm starting to get nice green and purple coralline over most of my rocks. The only down side is I'm burning through GFO every 2-3 weeks.

 

[sixty_reefer]

We are - I was responding to another post where you suggested that 'even humans have a Redfield ratio'. No one calculates that ratio either (just like the brick). I didnt get the point of why you can calculate the ratio of N and P in a human means anything with regards to reef aquaria - thats all

It depends if coral uses nitrogen in the same way as we do. As humans we use a vast amount of nitrogen daily in a gas form, it doesn’t make us fatter or more taller but we can’t survive without it for some reason.

 

[ZaneTer]

It depends if coral uses nitrogen in the same way as we do. As humans we use a vast amount of nitrogen daily in a gas form, it doesn’t make us fatter or more taller but we can’t survive without it for some reason.

Would you mind explaining how we use nitrogen gas? I am certain that it cannot be taken in through the lungs bar medical conditions and it certainly is not necessary to be exposed to. I have built hyperbaric systems for divers exposing them to Heliox (2% oxygen/ 98% helium) for 42 days at a time. Atmospheric nitrogen has no impact on humans.

On a side note nitrous oxide is critical for the development of an erection.

 

[ZaneTer]

Let’s try to sort through the opinions on here.
The argument that having near zero is fine because there must still be some excess is utterly ridiculous.

Oxygen content at sea level is roughly 21%. Of that we can only take in between 20 and 25% for each breath. That would lead someone to say that we have excess oxygen and it should be perfectly fine to drop it to 5%.

I can assure you that being exposed to 5% oxygen at sea level will most certainly kill you. Without a shadow of a doubt. Just because we can’t consume it in a single breath doesn’t mean that there is excess.

For anyone interested required oxygen concentration exposure scales with atmospheric pressure. At 30bar only 2% of your breathable gas can be oxygen. Any more will lead to oxygen poisoning and death.

 

[MnFish1]

It depends if coral uses nitrogen in the same way as we do. As humans we use a vast amount of nitrogen daily in a gas form, it doesn’t make us fatter or more taller but we can’t survive without it for some reason.

I have no clue what you're talking about. The red field ratio has nothing to do with intake. And Humans do not use 'nitrogen gas'. But its presence in the atmosphere prevents oxygen toxicity.

 

[Elegance Coral]

Let’s try to sort through the opinions on here.
The argument that having near zero is fine because there must still be some excess is utterly ridiculous.

Oxygen content at sea level is roughly 21%. Of that we can only take in between 20 and 25% for each breath. That would lead someone to say that we have excess oxygen and it should be perfectly fine to drop it to 5%.

I can assure you that being exposed to 5% oxygen at sea level will most certainly kill you. Without a shadow of a doubt. Just because we can’t consume it in a single breath doesn’t mean that there is excess.

For anyone interested required oxygen concentration exposure scales with atmospheric pressure. At 30bar only 2% of your breathable gas can be oxygen. Any more will lead to oxygen poisoning and death.

I think you're comparing apples and oranges. Coral are animals, like us. We, and they, don't need inorganic phosphate and nitrate at all. You could have absolute zero Inorganic N and P in the water and the coral could be just fine. The animal needs organic nitrogen and phosphorus, as we do, and all other animals.

Zooxanthellae do need inorganic N and P, but that does not mean they need X amount in the open water where they live. They too, could live just fine with zero inorganic N and P in the surrounding open water.

The coral animal feeds on organic material, like all other animals do. They also create waste from this feeding. When organics break down, or are digested, inorganics are produced. The coral animal can produce all the inorganic N and P, needed by its zooxanthellae through feeding on organic material. There is no NEED for ANY inorganic nitrate or phosphate in the surrounding open water. Provided, the animal is fed well.

Peace
EC

 

[IslandLifeReef]

Let’s try to sort through the opinions on here.
The argument that having near zero is fine because there must still be some excess is utterly ridiculous.

Oxygen content at sea level is roughly 21%. Of that we can only take in between 20 and 25% for each breath. That would lead someone to say that we have excess oxygen and it should be perfectly fine to drop it to 5%.

I can assure you that being exposed to 5% oxygen at sea level will most certainly kill you. Without a shadow of a doubt. Just because we can’t consume it in a single breath doesn’t mean that there is excess.

For anyone interested required oxygen concentration exposure scales with atmospheric pressure. At 30bar only 2% of your breathable gas can be oxygen. Any more will lead to oxygen poisoning and death.

My question is what would you define as near zero? Natural sea water has a typical NO3 reading of less than 0.1 ppm. It has a typical PO4 reading of 0.005 ppm. That seems to be enough excess for the coral and zooxanthellae, so readings of 10 ppm NO3 and .1+ PO4 are obviously more than the coral need. So, do we define near zero as less than natural sea water, or is it when our home tests kits say near zero? Even the error on the Hanna ULR phosphorus check is higher than the PO4 level in natural sea water.

 

[ZaneTer]

My question is what would you define as near zero? Natural sea water has a typical NO3 reading of less than 0.1 ppm. It has a typical PO4 reading of 0.005 ppm. That seems to be enough excess for the coral and zooxanthellae, so readings of 10 ppm NO3 and .1+ PO4 are obviously more than the coral need. So, do we define near zero as less than natural sea water, or is it when our home tests kits say near zero? Even the error on the Hanna ULR phosphorus check is higher than the PO4 level in natural sea water.

Do you mind if I ask for the link to the paper you pulled those figures from? I think you will find people like @Lasse have different figures for natural sea water to what you are working with.

The next point is our home reefs are a far cry from the ocean. The ocean is a vast 24hr supply of phytoplankton, zooplankton, minerals and indeed nitrate and phosphate (in surprisingly varied amounts)

Let’s pretend you need 100g of protein to survive. At your old home you got to eat fillet steaks and eggs. Now let’s pretend you were a very naughty boy and off to prison you go. You can kiss that steak and eggs goodbye. Now the only option available to you is soy powder. Yes it tastes horrendous but needs must to fulfil that 100g per day requirement.

People need to stop thinking that our tanks are the ocean. They are NOT.

 

[IslandLifeReef]

Do you mind if I ask for the link to the paper you pulled those figures from? I think you will find people like @Lasse have different figures for natural sea water to what you are working with.

The next point is our home reefs are a far cry from the ocean. The ocean is a vast 24hr supply of phytoplankton, zooplankton, minerals and indeed nitrate and phosphate (in surprisingly varied amounts)

Let’s pretend you need 100g of protein to survive. At your old home you got to eat fillet steaks and eggs. Now let’s pretend you were a very naughty boy and off to prison you go. You can kiss that steak and eggs goodbye. Now the only option available to you is soy powder. Yes it tastes horrendous but needs must to fulfil that 100g per day requirement.

People need to stop thinking that our tanks are the ocean. They are NOT.

You can find the article in the forums section under reef chemistry. It’s an article by @Randy Holmes-Farley.

Yes, the ocean has a vast supply of food for corals. However, almost all, if not all home PO4 test kits only test for inorganic PO4. Corals can’t use this, so having an excess of this is useless. Also, the zooxanthallea use N, which we don’t test for. As a matter of fact, as mentioned above, corals use a lot of organic nutrients that we can’t measure. So, using NO3 and PO4 to determine if your corals have enough food is the same as saying a 2 pound bag of unknown edible items a day is sufficient to maintain nutrition.

So again, can you quantify what near zero nutrients encompasses?

 

[ZaneTer]

You can find the article in the forums section under reef chemistry. It’s an article by @Randy Holmes-Farley.

Yes, the ocean has a vast supply of food for corals. However, almost all, if not all home PO4 test kits only test for inorganic PO4. Corals can’t use this, so having an excess of this is useless. Also, the zooxanthallea use N, which we don’t test for. As a matter of fact, as mentioned above, corals use a lot of organic nutrients that we can’t measure. So, using NO3 and PO4 to determine if your corals have enough food is the same as saying a 2 pound bag of unknown edible items a day is sufficient to maintain nutrition.

So again, can you quantify what near zero nutrients encompasses?

I am well aware of the article and that it is recirculated information with no basis on a scientific paper. I have great respect for Dr Holmes-Farley and certainly don’t question his skills as a chemist.

Kindly provide us with a link to a scientific document stating exact concentrations of sea water around the world. You will find it varies from area to area and greatly with changing ocean currents and upwellings.

In truth I have no answer for what constitutes “near zero” so let’s hear your answer to that question and the reasoning behind it.

Consider this: corals behave in many ways like plants yet nobody would dare question the need to provide a plant fertiliser. You may try to argue that they are different because some corals can capture prey items. So do some plants. When you take corals out of their natural habitat something must be substituted to account for the nutrient deficiency hence the need for nitrate and phosphate.

Corals can and certainly do uptake inorganic nitrate and phosphate directly. It is well documented and studied. I think the part you are stumbling over is the inorganic before the nitrate and phosphate. Just because it’s inorganic doesn’t mean it can’t be utilised by organisms.

A few references to INORGANIC nutrient uptake by corals:

Coral Uptake of Inorganic Phosphorus and Nitrogen Negatively Affected by Simultaneous Changes in Temperature and pH

The effects of ocean acidification and elevated seawater temperature on coral calcification and photosynthesis have been extensively investigated over the last two decades, whereas they are still unknown on nutrient uptake, despite their importance for coral energetics. We therefore studied the...

journals.plos.org

Nitrogen and phosphorus uptake rates of different species from a coral reef community after a nutrient pulse - Scientific Reports

Terrestrial runoff after heavy rainfall can increase nutrient concentrations in waters overlying coral reefs that otherwise experience low nutrient levels. Field measurements during a runoff event showed a sharp increase in nitrate (75-fold), phosphate (31-fold) and ammonium concentrations...

www.nature.com

High phosphate uptake requirements of the scleractinian coral Stylophora pistillata | Journal of Experimental Biology | The Company of Biologists

jeb.biologists.org

 

[Lasse]

IMO and in most of the articles I have read show a NO3 concentrations of around the figure you mentioned (0.1 - 0.3 ppm NO3) but the PO4 levels normally show around 0.04 ppm. The PO4 will alter because of reasons @ZaneTer mentioned - upwelling, land run off and currents.

However, almost all, if not all home PO4 test kits only test for inorganic PO4. Corals can’t use this, so having an excess of this is useless. Also, the zooxanthallea use N,

IMO - this is not the whole truth. Let us start with PO4. The coral animal does not use inorganic PO4 - its an animal and produce inorganic PO4 as a waste and relay on organic PO4 and other organic P sources for metabolism and growth. However - you maybe have heard about photosynthetic and nonphotosynthetic corals. The statement "PO4. Corals can’t use this," is valid for nonphotosynthetic corals but not for photosynthetic corals. 98 % of the corals we can have in aquarium is photosynthetic corals. They are photosynthetic because they host a microalgae inside their tissues - the zooxanthellae (zoox). This microalgae can only use inorganic PO4 as an P source for surviving and growth. It gets its P either from the inorganic PO4 the coral animal produce (when the coral animal is "eating") or from excess inorganic PO4 in the water column. The word excess is funny because it basically tell us what is not consumed of the compounds in our water. If a concentration of something is 0 - we do not know if it is a deficiency of that compound or if it is exactly what is needed. If you test a small excess - you are sure - there is enough of it. I agree that the concentration of certain compounds is not the most important and does not says how much the flux of it is. With flux I mean the sum of what is produced and consumed during a day. If we look at inorganic PO4 - it is produced by animals (the most important regarding this issue - heterotrophic bacteria) and consumed by plants (including algae). If the production is higher than consumption - you read a excess in the water - if the consumption is higher - you read zero! According to inorganic PO4 - there is always some reserves bound in the substrate (sand and rocks) as metal-PO4 or some forms of absorption. This this type of bindings - it is normally a relationship between bound and free (in the water column) species of the compound. If it is zero in the water column - the substrate will slowly leak inorganic PO4 into the water column. Slowly - the reserves will be emptied and when they are - the problem with inorganic PO4 deficiency will show up as bad coral health/growth - and sometimes as a outbreak of mat forming cyanobacteria. As I said before - there I get my information according inorganic PO4 concentrations from - it says around 0.04 ppm. This is also often around the detection limit (or the accuracy of the method) If I read 0.04 ppm with my low phosphorous Hanna checker - I know (if I have done right and use total cleaned equipment) that I have between 0.00 - 0.08 ppm inorganic PO4. That´s my "sweet spot" because if I read around this value - I know that I´m not using the reserves. If I read lower than 0.04 or 0 I know that I risk to use the reserves or really do it. If I have done this for a long time - I maybe need to add inorganic PO4 to the water. if I do - I must be carefully and measure rather often because - first I will read 0 during the times the reserves is building up (if adding + production of inorganic PO4 is higher than the consumption of it) and suddenly - they are filled up and I can read a concentration.

This long post was only about inorganic PO4 and reflects my personal opinion, describing how I managing my aquarium - and works for me. It is not the same as it would work in every aquarium but I try to base my husbandry on facts that I know for now - but I´m still in the learning curve.

I will come back later on according my view of inorganic N. Now my wife want go and shop before the invasion of some of the grandchildren Ice cream high on the shopping list

Sincerely Lasse