Is it OK to have zero nitrates with Core7?

[Tim Olson]

I'm really struggling to get nitrates above zero, while my phosphates are around 0.15-0.25 ppt (Hanna ULR).

Is it OK to have zero nitrates, if I'm using Core7 and a relatively large refugium? Since when I attempt to raise nitrates, with NeoNitro, many of the corals retract completely. Then after a few hours they recover. I'm only dosing 2ml/day for 3 days, for my 60 gallon system, which barely raises nitrates to 0.2 ppt. If I don't dose NeoNitro my corals are generally doing good/great.

I'm guessing that maybe the fuge and corals are consuming all the nitrates.

FYI, I've tried to raise nitrates 3 times in the last year and every time I get the same result.

Any help would be greatly appreciated, since I'm really confused.

 

[widarecu]

I’m having similar issues, before triton and more specifically the refugium my nitrates were through the roof and so were the phosphates, at that moment lost a few acroporas and in general thank was not doing great.

Once I started with Triton and a sizable refugium the phosphates started to go down slowly, things improved, better color and growth than ever but then nitrates reached zero and then new problems started, some corals lost color (mostly montiporas) and growth slowed down.

Testing with Hanna checker I was getting between 0.09 and 0.15, testing Nitrates with salifert I was in 0. After running my ICP I found out my phosphates are actually 0.02 which means Hanna checker is not that accurate (a few people are finding the same reading discrepancy).

Short story short (not that short), I started adding Aquaforest Aminoacids and Vitality since 2 weeks ago and I’ve notice an improvement, nitrates are now between 1 - 3 and color and growth are coming back.

 

[DancingWind]

I’m having similar issues, before triton and more specifically the refugium my nitrates were through the roof and so were the phosphates, at that moment lost a few acroporas and in general thank was not doing great.

Once I started with Triton and a sizable refugium the phosphates started to go down slowly, things improved, better color and growth than ever but then nitrates reached zero and then new problems started, some corals lost color (mostly montiporas) and growth slowed down.

Testing with Hanna checker I was getting between 0.09 and 0.15, testing Nitrates with salifert I was in 0. After running my ICP I found out my phosphates are actually 0.02 which means Hanna checker is not that accurate (a few people are finding the same reading discrepancy).

Short story short (not that short), I started adding Aquaforest Aminoacids and Vitality since 2 weeks ago and I’ve notice an improvement, nitrates are now between 1 - 3 and color and growth are coming back.

Hannah checker checks for bioactive Phosphates. ICP is a spectroscope - it only sees atoms. It does not mean its phosphate. these are 2 different tests.

But yeah .. no NO3 and PO4 is bad - get it somehow - feed more or reduce refugium photo period or dose.
But on the bright side its much simpler to add stuff to water than to remove.

 

[Tim Olson]

I’m having similar issues, before triton and more specifically the refugium my nitrates were through the roof and so were the phosphates, at that moment lost a few acroporas and in general thank was not doing great.

Once I started with Triton and a sizable refugium the phosphates started to go down slowly, things improved, better color and growth than ever but then nitrates reached zero and then new problems started, some corals lost color (mostly montiporas) and growth slowed down.

Testing with Hanna checker I was getting between 0.09 and 0.15, testing Nitrates with salifert I was in 0. After running my ICP I found out my phosphates are actually 0.02 which means Hanna checker is not that accurate (a few people are finding the same reading discrepancy).

Short story short (not that short), I started adding Aquaforest Aminoacids and Vitality since 2 weeks ago and I’ve notice an improvement, nitrates are now between 1 - 3 and color and growth are coming back.

Interesting similarities. It sounds like you're on the right track and have measurable nitrates. So, it seems that I should be able to as well.

For about the last 3 years I've never been able to get Nitrates above zero, and I think most or all that time was using Triton,

Phosphates, though, have been all over the map and up to a few month ago I was chasing 0.03 ppm. I usually would do that with GFO or Phosphate-E and the corals were OK to surviving. But then I got Dinos, one of the recommendations was to raise phosphates to 0.15+, so I let phosphates go high (~0,020 ppm) thinking the corals could die. Although, to my surprise, the corals significantly improved. They had much better polyp extension, color and growth. Also, the Dinos went away by adding a UV reactor and other methods.

I also use the Hanna ULR tester, but I've incorporated an adjustment factor that takes the last 2 ICP results into account. The adjustment takes the ULR reading and multiplies it by 1.397 to give the final reading. For example 30 ppb converts to 54.48 ppb.

So now some different kind of dinos has started, so I read that bringing up nitrates should help. I've been using the Salifert Nitrate test kit and have been getting 0.2 ppm. Every time I add NeoNitro, my corals react poorly. I also dose CoralAmino (Brightwell).

 

[Tim Olson]

Hannah checker checks for bioactive Phosphates. ICP is a spectroscope - it only sees atoms. It does not mean its phosphate. these are 2 different tests.

But yeah .. no NO3 and PO4 is bad - get it somehow - feed more or reduce refugium photo period or dose.
But on the bright side its much simpler to add stuff to water than to remove.

Thanks ... On feeding, what's weird is that if I feed more the Phosphates go up, but Nitrates stay at zero. How can that be? Maybe it's because the refugium takes out more Nitrates and Phosphates?

So, I'm going to take your advice and dial back the refugium. I currently run it 23 hours a day, so I'm going to reduce the lighting to 12 hours and see if that increases Nitrates. Although, I hope Phosphates don't go up too. We'll see.

 

[DancingWind]

Thanks ... On feeding, what's weird is that if I feed more the Phosphates go up, but Nitrates stay at zero. How can that be? Maybe it's because the refugium takes out more Nitrates and Phosphates?

So, I'm going to take your advice and dial back the refugium. I currently run it 23 hours a day, so I'm going to reduce the lighting to 12 hours and see if that increases Nitrates. Although, I hope Phosphates don't go up too. We'll see.

Well what is you macro composition? just cheto? But I have chateo (just this week removed most of it - testing if it is sucking up all the metals in the water), feather and grape caulerpa. No3 ~10-25, po4 0
My problem is that Po4 is at 0 by hanah LR if i don't do any crazy feeding or dosing.

 

[Tim Olson]

My main macro is Chaeto in the fuge. Although, I have a decent amount of hair algae in the display tank, which I leave, since the pods hang out there, so my Dragonets are happy. BTW, I feed heavily to keep the corals doing well, like my Sun Coral.

Hope your test goes well.

 

[widarecu]

Thanks ... On feeding, what's weird is that if I feed more the Phosphates go up, but Nitrates stay at zero. How can that be? Maybe it's because the refugium takes out more Nitrates and Phosphates?

So, I'm going to take your advice and dial back the refugium. I currently run it 23 hours a day, so I'm going to reduce the lighting to 12 hours and see if that increases Nitrates. Although, I hope Phosphates don't go up too. We'll see.

Just as a reference, I’ve always run my refugium inverse to the main lights 12 hours in total, in size it is just short of 10% the total of my display tank volume and it’s completely packed, literally nothing more than water can pass through.

My tank is about 750 liters with 26 fish including 10 big fat Anthias, Harlequin and a few tangs, I feed pellets 4 times a day (3 turns of the auto feeder each time) + 3 squares of frozen food daily. That’s quite a lot of food, my last 3 ICPs came as 0.019, 0.028, 0.014 while I was doing auto water changes which I stoped about 1 month ago trying to get parameters a bit higher.

 

[DancingWind]

My main macro is Chaeto in the fuge. Although, I have a decent amount of hair algae in the display tank, which I leave, since the pods hang out there, so my Dragonets are happy. BTW, I feed heavily to keep the corals doing well, like my Sun Coral.

Hope your test goes well.

That is weird ... but then again you can always does No3 - there are commercial options for reef tank and the diy from the stores gardening section

 

[Tim Olson]

That sounds like a nice system!

Now I'm wondering if my 10 gallon refugium is too big, since it's it's 25% of my display tank volume. Also, like yours, it's densly packed, and I have to pull out 1-2 gallons of chaeto every week or so. So that might explain why my Nitrates are always zero, but why are my phosphates so high?

I feed a lot of food, for my 40 gallon display tank, including 2 cubes of Mysis, about 1/4 teaspoon of Reef Roids and some pellet food day. I have 2 Clowns, 1 Chromis, 1 big Mandarin Dragonet and 2 Ruby Red dragonets.

My guess is that Chaeto consumes Nitrates at a higher rate than Phosphates, but I haven't been able to find any research to confirm or deny that.

Also, to raise Nitrates, yesterday I reduced the refugium lighting to 12 hours/day. Also, down the road, I'm considering turning off my skimmer and removing significantly more Chaeto every week.

 

[Tim Olson]

That is weird ... but then again you can always does No3 - there are commercial options for reef tank and the diy from the stores gardening section

Thanks ... So, it looks like I should be investigating other options for adding Nitrates, since NeoNitro hurt my corals. Maybe there are other ingredients in NeoNitro that are causing the problem vs. just using straight Nitrates.

 

[widarecu]

That sounds like a nice system!

Now I'm wondering if my 10 gallon refugium is too big, since it's it's 25% of my display tank volume. Also, like yours, it's densly packed, and I have to pull out 1-2 gallons of chaeto every week or so. So that might explain why my Nitrates are always zero, but why are my phosphates so high?

I feed a lot of food, for my 40 gallon display tank, including 2 cubes of Mysis, about 1/4 teaspoon of Reef Roids and some pellet food day. I have 2 Clowns, 1 Chromis, 1 big Mandarin Dragonet and 2 Ruby Red dragonets.

My guess is that Chaeto consumes Nitrates at a higher rate than Phosphates, but I haven't been able to find any research to confirm or deny that.

Also, to raise Nitrates, yesterday I reduced the refugium lighting to 12 hours/day. Also, down the road, I'm considering turning off my skimmer and removing significantly more Chaeto every week.

I think you’ll start seeing improvements with the reduction to 12 hours for the refugium light. I assume you have stopped your water changes as well right?

Ohhh and one more thing I don’t do is trimming, last time I trimmed my Chaeto was about 3 months ago, the only thing I do now is once a week submerge it a bit to clean the surface as it develops some weird foam.

 

[Tim Olson]

I think you’ll start seeing improvements with the reduction to 12 hours for the refugium light. I assume you have stopped your water changes as well right?

Ohhh and one more thing I don’t do is trimming, last time I trimmed my Chaeto was about 3 months ago, the only thing I do now is once a week submerge it a bit to clean the surface as it develops some weird foam.

Cool ... I hope so, since that's an easy change. Also, I've cut back on my water changes to 10-14 days, but I haven't stopped them yet. I'll extend the days and see what happens. That should also help my continued Dinos problem, from what I understand.

On the Chaeto, I turn it over every couple of days, so it doesn't get burned by my Kessil H380. Also, reducing the lighting schedule should reduce the growth, so I won't have to remove Chaeto as often. If I don't remove some, it literally will start getting pushed out of the water.

BTW, thanks for all the help!

 

[widarecu]

Cool ... I hope so, since that's an easy change. Also, I've cut back on my water changes to 10-14 days, but I haven't stopped them yet. I'll extend the days and see what happens. That should also help my continued Dinos problem, from what I understand.

On the Chaeto, I turn it over every couple of days, so it doesn't get burned by my Kessil H380. Also, reducing the lighting schedule should reduce the growth, so I won't have to remove Chaeto as often. If I don't remove some, it literally will start getting pushed out of the water.

BTW, thanks for all the help!

Cool!!! Now it’s just wait and see, let me know how it goes with the days, interested to see your results to compare

 

[Tim Olson]

Will do!

As of today, with 12 hour lighting on the fuge, Nitrates have gone back to zero, phosphates are 0.214 ppm and alkalinity went up. Obviously way too early to tell.

 

[widarecu]

Will do!

As of today, with 12 hour lighting on the fuge, Nitrates have gone back to zero, phosphates are 0.214 ppm and alkalinity went up. Obviously way too early to tell.

Exactly you need to give it time, at least a week of testing to get a sense the direction parameters are going ... all about patience which I don’t have much lol

 

[Tim Olson]

After thinking about this some more, I decided to do more research regarding the relative uptake of Nitrogen and Phosphorus in macroalgae and Chaeto.

I've always had, in the back of my mind, the Redfield Ratio, which is 16:1 Nitrogen to Phosphorus present in macroalgae. But that didn't answer what the Nitrogen & Phosphorus uptake is for Chaeto. So, I read a few scholarly articles and also found two threads that helped.

The first one was Phosphate inhibiting nitrate uptake in chaetomorpha (experiment and results), where his experiments reduced Nitrogen to zero by adding phosphates. This seems counter intuitive, but it worked.

The second thread was by Randy Holmes-Farley - Reef Chemistry Question of the Day #185 Macroalgae and Nutrient Uptake. "The exact ratio of nitrogen to phosphorus in macroalgae reflects what it took up from the water. This ratio depends not only on the species involved, but, in some cases, on the concentrations of nutrients available to it since they can take up somewhat more N (nitrogen) or P (phosphorus) when more is available." The answer was that macroalgae uptakes 20 times more Nitrogen than Phosphorus.

So, my somewhat ignorant conclusion is that I've driven down Nitrogen to zero by having more Phosphates. In other words, the Chaeto is consuming 20 ppm for every 1 ppm Phosphates.

Does this make any sense?

 

[IslandLifeReef]

After thinking about this some more, I decided to do more research regarding the relative uptake of Nitrogen and Phosphorus in macroalgae and Chaeto.

I've always had, in the back of my mind, the Redfield Ratio, which is 16:1 Nitrogen to Phosphorus present in macroalgae. But that didn't answer what the Nitrogen & Phosphorus uptake is for Chaeto. So, I read a few scholarly articles and also found two threads that helped.

The first one was Phosphate inhibiting nitrate uptake in chaetomorpha (experiment and results), where his experiments reduced Nitrogen to zero by adding phosphates. This seems counter intuitive, but it worked.

The second thread was by Randy Holmes-Farley - Reef Chemistry Question of the Day #185 Macroalgae and Nutrient Uptake. "The exact ratio of nitrogen to phosphorus in macroalgae reflects what it took up from the water. This ratio depends not only on the species involved, but, in some cases, on the concentrations of nutrients available to it since they can take up somewhat more N (nitrogen) or P (phosphorus) when more is available." The answer was that macroalgae uptakes 20 times more Nitrogen than Phosphorus.

So, my somewhat ignorant conclusion is that I've driven down Nitrogen to zero by having more Phosphates. In other words, the Chaeto is consuming 20 ppm for every 1 ppm Phosphates.

Does this make any sense?

Yes, this makes sense.

Since you aren't using anything other than chaeto to remove NO3, your system has NO3 available, just not measurable with your testing. If you didn't have any NO3, your chaeto would die.

What you are experiencing is a system that is out of balance and is NO3 limited. What this means is that you have more PO4 available than NO3. To further add to the conundrum, PO4 binds to rock and other substrate. As the PO4 is removed from the water, it is then released from the substrate to bring the system back into PO4 balance. So, reducing PO4 can take time.

What I would recommend is what was suggested earlier. Dose NO3 into your system so that it is no longer NO3 limited. Over time, the available NO3 will allow the chaeto to consume more PO4. You will probably have to trim you chaeto more often due to more growth, but in time, your system will get into a nutrient balance between NO3 and PO4.

The key is to go slow. As long as your tank inhabitants look good, there is no reason to make drastic changes.

 

[Tim Olson]

@IslandLifeReef ... Thank you for insights on this. It sure makes a lot of sense. Do you think the current plan of reducing the lighting period on the refugium is the right way to go?

I'm still confused, though. When my Phosphates were 0.03 ppm and Nitrates at 0.0 ppm, the corals were doing what I thought was OK. But when I started feeding like crazy (to get rid of Dinos) they really took off, along with Phosphates. Then, every time I've tried to increase Nitrates the corals go south.

So, I guess I should stay the course and try to increase slowly

 

[IslandLifeReef]

@IslandLifeReef ... Thank you for insights on this. It sure makes a lot of sense. Do you think the current plan of reducing the lighting period on the refugium is the right way to go?

I'm still confused, though. When my Phosphates were 0.03 ppm and Nitrates at 0.0 ppm, the corals were doing what I thought was OK. But when I started feeding like crazy (to get rid of Dinos) they really took off, along with Phosphates. Then, every time I've tried to increase Nitrates the corals go south.

So, I guess I should stay the course and try to increase slowly

Reducing the lighting in the refugium will allow NO3 to increase, but also PO4. Unless you add NO3 without adding PO4, you will stay in this unbalanced state.

I would recommend you start dosing NO3. Start slowly, and then gradually increase you NO3 dosing until you see PO4 start decreasing. At that point, I would keep your NO3 dosing where it is until your PO4 gets to a level of .1 or less. Keep an eye on your coral during this. If they look unhappy, pause for a week or two, and then continue once they look happy again.