Carbon limited reef?

[captainbeardly]

So are you saying I should just continue adding the recommended 2.5mL per day until I get a reading of 0.02? I'm on day 4 of that and it makes me nervous adding so much phosphate into the tank. If the equation on the bottle is correct, this is enough phosphate to be at 0.08 over 4 days but has gotten me nowhere. Which would mean there is some form of phosphate sink absorbing everything I'm dosing. I just added today's dose roughly an hour ago and I tested phosphate and it is still 0.00. The only thing I found that could be the issue other than 2 faulty tests from two separate companies, which seems unlikely, is "In a low phosphate situation, some portion of the added phosphate will bind to calcium carbonate surfaces, lowering the actual amount in the water."

If your nitrates are staying stable then yes I would keep dosing small amounts of phos until you get a reading. Once you get a reading then go from there to maintain it. A 0.02 phos increase isn’t really enough to worry about. Honestly I’d only increase it 0.01 until you get a reading then maintain whatever level you want just don’t exceed 0.1 on your phosphates. Rock sand corals ect will soak it up till it’s balanced out. Eventually you will get a reading. Just don’t change too many things at one time. Like feeding. Keep your normal feeding schedule. It’s easier to control how much phos is in your tank with the additive then with food.

 

[Lavey29]

Lots of good info for the OP here. My tank bottomed out phosphates also and it took about a week of double dosing before I started to see some measurable phosphates. I am using the brightwell solution also. I had to dose nitrate also to bring that up even with 5 fish and feeding 3x per day.

 

[Nano sapiens]

So are you saying I should just continue adding the recommended 2.5mL per day until I get a reading of 0.02? I'm on day 4 of that and it makes me nervous adding so much phosphate into the tank. If the equation on the bottle is correct, this is enough phosphate to be at 0.08 over 4 days but has gotten me nowhere. Which would mean there is some form of phosphate sink absorbing everything I'm dosing. I just added today's dose roughly an hour ago and I tested phosphate and it is still 0.00. The only thing I found that could be the issue other than 2 faulty tests from two separate companies, which seems unlikely, is "In a low phosphate situation, some portion of the added phosphate will bind to calcium carbonate surfaces, lowering the actual amount in the water."

Yes, you'll need to keep adding PO4 until you get a reading. I did this by feeding and it took quite a few days to finally get a 0.02 ppm reading.

The Neophos instructions assume that if PO4 drops from 0.02 to '0' then the system is not carbon limited. While this may be the case, following what happens to the NO3 over the same period would be more telling IMO. For example, if NO3 doesn't drop some along with the PO4, then I'd argue that a system is still carbon limited (reefers most often carbon dose specifically to reduce NO3, with PO4 reduction as a side effect).

 

[Big E]

You need to know your daily consumption. The only way to do that is to dose enough Neophos to get a reading high enough so you can measure this.....test it about 15 minutes after you dose. 24 hours from that time test again & that will give you your daily consumption.

It will take a few days to get a handle on this. Once you can consistently keep your P04 stable the next job is to fix the cause of your depleting P04.
This may mean reducing your export system or adding more fish or you can also use something like Reef Roids.

I would only consider dosing Neophos to get things in order short term. It's treating the symptom not the cause.

Don't be afraid to dose. I would dose to get at least .10 to start.

Ignore the carbon dosing part just dose the Neophos and measure. If your P04 is zero you're phosphate limited and the bacteria won't grow.

Don't concern yourself with dosing a carbon source unless your nitrates are too high and you already have a consistent level of P04.

 

[Karliefish]

I was dosing Phosphates. How long have you been dosing? It can take a while for it to start to show up. You want to go slow to avoid a sudden spike.
Also I have switch from liquid phosphates to Spirulina powder and ReefRoids.

From the Moonshiner's handbook:
Phospates (Now Spirulina Powder)
If Po4 is desired to be increased, I recommend the use of Spirulina super food to be used. This is organic addition of Po4, and gentle use will show effects after a few days. I recommend usually to supplement 1-2 Mini spoons as from Red Sea Pro Test kits per 100G per day and adjust after a few days. Please bear in mind that tanks which were starving from Po4 for a longer time, usually consume a lot more in the first few days until saturated and levels begin to raise, so watch out for this sudden effect to avoid Po4 spikes at the end.

Which phosphate product were you dosing? Have you completely switched to Spirulina Powder? I have a very large tank (380G) and I’m wondering how long it will take me to get Phosphates to to register using the Spirulina Powder method?

 

[MGarrison]

Which phosphate product were you dosing? Have you completely switched to Spirulina Powder? I have a very large tank (380G) and I’m wondering how long it will take me to get Phosphates to to register using the Spirulina Powder method?

I was dosing Loudwolf Sodium Phosphate. I have approximately 300 gallons total water volume.
1 Gallon RO Water w/ 90 grams Sodium Phosphate
1ml of Solution = 0.01 ppm in 300 gallons according to James' Planted Tank.

I am now only dosing Spirulina powder, I range between 0.03 - 0.08 ppm on Hanna Phosphorus ULR. I test twice a week (Wednesday and Sunday). I auto feed 3 times a day and feed 2 cubes of frozen once. I mix one mini spoon full to the frozen while I thaw it out. I also occasionally feed ReefRoids.

As far as how long it will take you, it will depend. All I can say is go slow and test often. I was liquid dosing until I got stable readings, then slowly switch over to spirulina.

 

[Karliefish]

I was dosing Loudwolf Sodium Phosphate. I have approximately 300 gallons total water volume.
1 Gallon RO Water w/ 90 grams Sodium Phosphate
1ml of Solution = 0.01 ppm in 300 gallons according to James' Planted Tank.

I am now only dosing Spirulina powder, I range between 0.03 - 0.08 ppm on Hanna Phosphorus ULR. I test twice a week (Wednesday and Sunday). I auto feed 3 times a day and feed 2 cubes of frozen once. I mix one mini spoon full to the frozen while I thaw it out. I also occasionally feed ReefRoids.

As far as how long it will take you, it will depend. All I can say is go slow and test often. I was liquid dosing until I got stable readings, then slowly switch over to spirulina.

Great information here. Is this the particular product you used? One more question…did you dose this throughout the day or dump it in all at once? What time of day and did you turn any part of your system off? So appreciate your assistance!

 

[MGarrison]

Great information here. Is this the particular product you used? One more question…did you dose this throughout the day or dump it in all at once? What time of day and did you turn any part of your system off? So appreciate your assistance!

I used Trisodium Phosphate per other threads that Randy suggested. I dosed once a day before lights came on and did not turn off anything.

 

[Karliefish]

I used Trisodium Phosphate per other threads that Randy suggested. I dosed once a day before lights came on and did not turn off anything.

Thank you so much for taking time to help me. I assume having been through this whole process you’ve been happy and more importantly your corals are happy with the results?

 

[Brian Berry]

​

Brightwell Neophos Instructions:​

Instructions and Guidelines​

Shake product well before using. Do not overdose. Results will be most significant when the system is being dosed with MICROBACTER7 on a daily or bi-daily basis.


1. Using accurate test kits or calibrated digital testing devices, determine phosphate and nitrate concentrations in system. It is assumed that the phosphate concentration in the system is below detectable limits for the testing method being employed.


2. Apply NEOPHOS as directed below to attain a phosphate concentration of ~0.02 ppm.


3. Allow 24-hours to elapse; re-test nitrate and phosphate concentrations. If concentrations remain unchanged, then the system is likely carbon-limited. Dose with REEF BIOFUEL at the rate of 1-ml per 25 US-gallons and allow 24-hours to elapse, then re-test phosphate and nitrate concentrations. Continue daily dosing with REEF BIOFUEL until phosphate or nitrate concentrations begin to decrease, indicating that the rate of carbon input to the system
matches the rate of phosphorus- or nitrogen-input, respectively.


4. If nitrate concentration decreases without addition of REEF BIOFUEL or use of KATALYST, phosphate concentration in the system will decrease. Continue dosing with NEOPHOS to maintain phosphate concentration
of ~0.01 - 0.02 ppm until nitrate concentration falls to within desired range (suggested 3 - 5 ppm). Thereafter, dose with NEOPHOS as required to maintain desired phosphate and nitrate concentrations.


Note: If at any time, dosing with NEOPHOS results in a prolonged increase of phosphate concentration without gradual decrease as nitrate is taken up, system is likely carbon-limited (remedied by the application of REEF BIOFUEL or KATALYST to the system). Refer to Steps 3 and 4, or to our website (NEOPHOS "Technical" page).

Basically, what they are saying is consistent with carbon dosing theory/practice as I understand it. There is always an inherent risk when carbon dosing of bottoming out nutrients, so that's why it's mostly recommended for advanced reefers.

All I can say from prior experience is that you need to take it REALLY slow and test often to make sure you aren't reducing nutrients too far and/or too fast. It certainly does the job and in my case (lower dose vinegar) it took NO3 down to ~2 ppm, but it also took PO4 too low as I too normally can't get a PO4 reading (sorry SPS ). Currently, I have elevated NO3 from daily feeding a type of NPS and so have implemented a very low carbon dosing regimen using vinegar (acetic acid) and an increase in the usage of high phosphate foods (Green superfoods which are mainly spirulina algae and high phosphate flake food) over other types of low phosphate foods.

I think great advice. For myself I would have gone too fast. My phosphate ranges from .00 to .02 but usually .00.

 

[Randy Holmes-Farley]

FWIW, I find those directions strange and product sales oriented, and I do not recommend following them.

it is normal and appropriate for reef tanks to be organic carbon limited for consumption of N and P, just like the ocean. That is not a problem that needs solving by adding organic carbon.

 

[hiphop]

I am currently in the same situation with my tank. That is how I came across this forum. was your po4 ever corrected, what was the end result?

 

[Randy Holmes-Farley]

I am currently in the same situation with my tank. That is how I came across this forum. was your po4 ever corrected, what was the end result?

What situation exactly?

 

[Edgecrusher28]

FWIW, I find those directions strange and product sales oriented, and I do not recommend following them.

it is normal and appropriate for reef tanks to be organic carbon limited for consumption of N and P, just like the ocean. That is not a problem that needs solving by adding organic carbon.

Can you expand on this in laymen terms? I ask because it is mentioned in a Red Sea NoPox manual that "Micro-biological reduction of algae nutrients occur naturally in all anoxic areas of the aquarium. This bacteria activity Is limited by the availability of suitable carbon sources and mineral co-factors and under normal conditions is unable to reduce all of the algae nutrients."

 

[Randy Holmes-Farley]

Can you expand on this in laymen terms? I ask because it is mentioned in a Red Sea NoPox manual that "Micro-biological reduction of algae nutrients occur naturally in all anoxic areas of the aquarium. This bacteria activity Is limited by the availability of suitable carbon sources and mineral co-factors and under normal conditions is unable to reduce all of the algae nutrients."

I certainly do not disagree with that (except the last sentence on mineral cofactors being limited; that may or may not be true in any given system). It's the premise for all types of organic carbon dosing (NOPOX, vinegar, vodka, sugar, etc.).

Basically what it means is that bacteria are hanging out waiting for food (which in this case, are small organic molecules such as ethanol). When they find it, they grow. When the grow they add tissue mass, and that tissue mass contains many things, including N, P, and a host of trace elements, all of which get reduced in the water due to dosing the organic carbon food.

That process happens all over the aquarium. Other organisms besides bacteria also consume these organics, including sponges, corals, cyanobacteria, etc.

In one particular part of the aquarium, where oxygen may be or may become low (such as down in a sand bed or in rock pores or maybe even on the bottom of a layer of bacteria in contact with the bulk water), another process takes place. That process is called denitrification, and it means that bacteria are using nitrate in place of oxygen in the metabolism of the added organics. That process drops nitrate without altering phosphate or trace elements. The existence of that process is one reason that organic carbon dosing often impacts nitrate far more than phosphate (the other being that bacteria bodies require a lot more N than P).

 

[Edgecrusher28]

I certainly do not disagree with that (except the last sentence on mineral cofactors being limited; that may or may not be true in any given system). It's the premise for all types of organic carbon dosing (NOPOX, vinegar, vodka, sugar, etc.).

Basically what it means is that bacteria are hanging out waiting for food (which in this case, are small organic molecules such as ethanol). When they find it, they grow. When the grow they add tissue mass, and that tissue mass contains many things, including N, P, and a host of trace elements, all of which get reduced in the water due to dosing the organic carbon food.

Is this the bacteria that is begin added by the carbon/vodka dosing?

That process happens all over the aquarium. Other organisms besides bacteria also consume these organics, including sponges, corals, cyanobacteria, etc.

In one particular part of the aquarium, where oxygen may be or may become low (such as down in a sand bed or in rock pores or maybe even on the bottom of a layer of bacteria in contact with the bulk water), another process takes place. That process is called denitrification, and it means that bacteria are using nitrate in place of oxygen in the metabolism of the added organics. That process drops nitrate without altering phosphate or trace elements. The existence of that process is one reason that organic carbon dosing often impacts nitrate far more than phosphate (the other being that bacteria bodies require a lot more N than P).

Interesting, how come most aquarium filters make an effort to oxygenate its media if denitrification is more effective in anoxic areas? Is that more of a freshwater carryover then marine?

 

[Randy Holmes-Farley]

Is this the bacteria that is begin added by the carbon/vodka dosing?

Interesting, how come most aquarium filters make an effort to oxygenate its media if denitrification is more effective in anoxic areas? Is that more of a freshwater carryover then marine?

Nitrification (ammonia to nitrate) requires O2. Denitrification (usually nitrate to N2, if it happens at all) happens in low O2.

carbon dosing does not add new bacteria, but the ones already in the tank multiply.

 

[mk_reefs]

I am currently in the same situation with my tank. That is how I came across this forum. was your po4 ever corrected, what was the end result?

How did you get yours figured out? I've been wiping phos clean same as the beginner of this thread stated, today I finally dosed 8ml over the course of 12hrs to achieve 0.03 and this is in 20 gallons.

 

[Randy Holmes-Farley]

How did you get yours figured out? I've been wiping phos clean same as the beginner of this thread stated, today I finally dosed 8ml over the course of 12hrs to achieve 0.03 and this is in 20 gallons.

This issue, which likely results from phosphate binding to rock and sand, is easy to fix with sufficient dosing of phosphate.

 

[mk_reefs]

This issue, which likely results from phosphate binding to rock and sand, is easy to fix with sufficient dosing of phosphate.

I do have rock no sand run bare bottom. Today I got a reading at the end of the day dosing 3ml 0.04 which I'm happy with well see if it can keep up this time.