Phosphate and Nitrate relationship

[DottyClown]

Recently, due to poor husbandry, I had a bloom of Turf Algae.  Phosphate was 1-2 while Nitrate was a staggering 100+.

Now Phosphate has been brought down to undetectable (at least on my API test kit), but Nitrate still hovers at 40.  Turf Algae growth stopped/slowed-down, but still there.

The Nitrate level quite stubborn and just won't drop.  I read that we actually need some Phosphate, in order for the bacteria to reduce the Nitrate.  Is this correct?  If so, does that mean I need to remove my RowaPhos and allow Phosphate to increase?

Currently using RowaPhos, Purigen and a little remaining Biosphere for chemical filtration.

Could anyone offer some advice, thanks.

[pcw]

Biologically, nitrates and phosphates are used up in accordance with the Redfield ratio. That is, carbon: nitrogen: phosphorous, 106:16:1 ratio. So having zero phosphates would indeed make it harder for bacteria to reduce nitrate. However, it is usually the case that zero nitrates detected on test kits merely indicate that the levels are low, rather than phosphates actually being completely absent. The biological process should still be occur.

That being said, since this form of reduction of nitrates and phosphates occurs biologically, it should not affect the ability of purigen in removing nitrates.

[DottyClown]

So meaning I can just leave the RowaPhos running in the tank?

Guess I just wait another week or 2 and see how the Nitrates level go.

[dsam]

I am currently experiencing this issue. Undetectable PO4 and NO3 forever at 25ppm. I have since stopped my FR with Rowasphos and hope the PO4 can up abit.

Now dosing with vinegar and doing regular water change and monitoring the situation.

[julius]

Biologically, nitrates and phosphates are used up in accordance with the Redfield ratio. That is, carbon: nitrogen: phosphorous, 106:16:1 ratio. So having zero phosphates would indeed make it harder for bacteria to reduce nitrate. However, it is usually the case that zero nitrates detected on test kits merely indicate that the levels are low, rather than phosphates actually being completely absent. The biological process should still be occur.

That being said, since this form of reduction of nitrates and phosphates occurs biologically, it should not affect the ability of purigen in removing nitrates.

purigen does not remove nitrate. It absorbs some form of dissolved organic. If these form of dissolved organic were to break bacteria, nitrate would increase. That is why the label states it help to CONTROL ammonia, niitrite and nitrate.

[patricklhc]

What bro pcw mention is correct. Redfield ratio. Since u do not have sufficient po4 for bacterials to use I would suggest u remove your po4 removal. Alternatively u can consider adding no3 removal to help speed up the process. Personally I would suggest u remove po4 removal for the time being.

Sent from my iPhone using Tapatalk

[pcw]

Cool learnt something new. I've never used purigen before. But in any case, I guess purigen should remain helpful in controlling the precursors to nitrates.

[Lee Hon Myung]

I am currently experiencing this issue. Undetectable PO4 and NO3 forever at 25ppm. I have since stopped my FR with Rowasphos and hope the PO4 can up abit.

Now dosing with vinegar and doing regular water change and monitoring the situation.

Sorry to bring this back up. did dosing vinegar help in bringing down NO3 despite having undetectable reading on PO4?

[sherman]

Vinegar dosing will reduce your NO3 but its good to have a little PO4 

[sharonleong]

For the expert how to really strike the balance?

For a stable tank what the best parameter for phosphate and nitrate?

[SantaMonica]

It's good to realize that the food you feed has very large amounts of nutrients N and P. So when you feed, you are resetting the N and P ratio. Therefore, usually, there is no need to focus on the ratio.

[sherman]

Just make sure yr PO4 is not zero. Anything less then 0.08 is ok