Lower nitrates by raising phosphate??

OREGONIC

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I have had an issue getting my nitrates to drop below 10ppm. Let me start with my tank information and parameters. I have a e170 that i have added a sump to. Run the hydra 26 hd that came with the tank on a slightly modified setting that BRS came up with to replicate the coral lab. 200-250 par at top of scape 80-120 at sand bed. I have 2 gyres mounted to left and right side of tank, the run a few diff cycles a day They ramp up for 15 min a day enough to move some sand around to keep things from setteling. Have about 3-4x hour turnover frm tank through sump with a curve 5 skimmer and a basket of bio media. Use filter floss in place of sock and change out every 3-4 days. I have converted the ato that came with the red sea sump to a ATS. I dose 38ml of Aquaforest a+b+c+ to keep parameters stable. I also have been dosing 2.5 ml of nopox a day, may be the issue. Parameters are:
Salinity 1.0255
Alk 7.9dkh
Cal 430
Ammonia and nitrates 0
Nitrate 10-12
Phosphate 0-.02
Magnesium 1450
Ph fluctuates between 8.07-8.25
Temp 77.7-78.0
I cant seem to keep any acros have killed about 6-7 frags over the last 6 months. They seem to be ok for about 2-3 weeks after adding then either rtn overnight or stn over the period of 1-2 weeks. Other sps like montis seem to do fine in my tank colors are jus slight washed out but they grow fairly quick. I have one mili that seems to stay alive in my tank and has even colored up slightly but is not growing and has no pe that I have seen since adding to my system. My ats has never really taken off like some i see but does grow some hair algae and gets some slime on it to. After tons of reading I have come to the theory that my nitrates are to high and phosphates are to low. I went a month doing a 10% water change every 3 days and my nitrates seemed to just jump back up to 10 within 48 hrs. I am considering raising my phosphates to .07-.10 in hopes that my nitrates will be more easily consumed. If I do this should I stop carbon dosing? Should i add nitrifying bacteria when dosing phosphate? Should I continue carbon dosing and dose bacteria at same time? Or is there something else all together I should try?
 

Randy Holmes-Farley

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It is much more likely that the acros are starving from lack of sufficient phosphate than that the nitrate is causing issues.

I’d aim for a level around 0.02-0.03 ppm by dosing or feeding more.
 
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OREGONIC

OREGONIC

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It is much more likely that the acros are starving from lack of sufficient phosphate than that the nitrate is causing issues.

I’d aim for a level around 0.02-0.03 ppm by dosing or feeding more.

Wouldnt feeding more drive nitrates up even further in return throwing the balance of the two further off? I use the red sea phosphate test kit and I do get a very sligh change in color but not as vibrant as the .02 should be. I will probably order a hanna checker as I feel it may be more accurate then attempting to see the slight color change with the eye. Should I stop dosing nopox if I try feeding heavier?
 

Randy Holmes-Farley

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Wouldnt feeding more drive nitrates up even further in return throwing the balance of the two further off? I use the red sea phosphate test kit and I do get a very sligh change in color but not as vibrant as the .02 should be. I will probably order a hanna checker as I feel it may be more accurate then attempting to see the slight color change with the eye. Should I stop dosing nopox if I try feeding heavier?

It might, but a bit higher nitrate is less of a concern than no phosphate (IMO). I'd pick dosing phosphate first, but was just offering another option. I wouldn't stop organic carbon dosing.
 
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OREGONIC

OREGONIC

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Sounds good.

Good luck and let us know what happens. :)

So I have been dosing neo phos for a few months now and I have noticed some changes. First colors of all corals have inhanced. I have 2 acros that have lasted several months now, they are not really growing and not any pe but have remained alive. My nitrates are still higher then I would like, 5ish range, even with less frequent water changes. The nitrates dropped pretty quickly after begining dosing phosphates. My tank still comsumes phosphates at a much quicker un balanced rate then nitrates. I have been dosing 1 occasionally 2ml every 2-3 days during this time. When i test the next day phosphates are just detectable using red sea test kit.

I have come up with a theory to why my phosphates are consumed at such a faster rate but unsure if it could actually be the cause. Last year I had asked the question is vaping near a reef tank safe and @Randy Holmes-Farley said “Every ingredient you listed, including flavoring and nicotine can act as a carbon source for bacteria. But it isn’t a big deal if that happens, and you’ll know why.” Os it possible that this carbon source feeds a bacteria that comsums phosphates at an uneven ratio to nitrates?
 

Randy Holmes-Farley

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Phosphate binds in large amounts to calcium carbonate surfaces. That is likely where a lot of the phosphate is going. It’s incredible how much can bind when none is there to start with.
 

Rick Gaas

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Phosphate binds in large amounts to calcium carbonate surfaces. That is likely where a lot of the phosphate is going. It’s incredible how much can bind when none is there to start with.

If dosing inorganic PO4 (Na3PO4), will the binding slow down over time? I have been dosing trisodium phosphate for the last week and it keeps dropping back down to where I was before I dosed. I test after dosing, to my target level of 0.25ppm and in 24hrs it is back down to 0.10ppm.
 

Randy Holmes-Farley

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If dosing inorganic PO4 (Na3PO4), will the binding slow down over time? I have been dosing trisodium phosphate for the last week and it keeps dropping back down to where I was before I dosed. I test after dosing, to my target level of 0.25ppm and in 24hrs it is back down to 0.10ppm.

The amount that binds to rock and sand is a function of how high the concentration is in solution. So at a fixed level (say, 0.02 ppm), you will eventually reach an equilibrium and no more will bind at that level.

If you try to raise the level high, more will bind. If you try to lower it, some will come off the rock surface.
 

Rick Gaas

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The amount that binds to rock and sand is a function of how high the concentration is in solution. So at a fixed level (say, 0.02 ppm), you will eventually reach an equilibrium and no more will bind at that level.

If you try to raise the level high, more will bind. If you try to lower it, some will come off the rock surface.

Thank you Randy. So just continue to dose to my target range and eventually it will reach that equilibrium?
 

Randy Holmes-Farley

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Thank you Randy. So just continue to dose to my target range and eventually it will reach that equilibrium?

Yes, but recognizing that much is being bound, its fine to dose more than your target and keep monitoring. :)
 

Erpiki

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Did that work? I also have that isue with low phosphates and high nitrates, I would like to buy trisodium phosphate to try it but I am not sure if the one they sell in shops for agriculture will be good, can you tell me where did you bought yours? Thank you.
 

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Brightwell Neophos is a PO4 additive in liquid form made for the aquarium hobby. It is available online and is inexpensive. Dosing instructions are right on the bottle too.
 

Steve1500

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Did that work? I also have that isue with low phosphates and high nitrates, I would like to buy trisodium phosphate to try it but I am not sure if the one they sell in shops for agriculture will be good, can you tell me where did you bought yours? Thank you.
I use the phosphate from this site. Having good success with it. Tried Neophos and it did not work nearly as well as this. http://greenleafaquariums.com/
 

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