Super high phosphate

[Cthulukelele]

Oh, OK, I though *** was a recommended value.

Lol that spacing mistake made a dirty word that got beeped by r2r!

My most succesful tank, a mixed reef thrives with PO4 at 0.5 and a bit higher at times.

Yeah I really feel like for the most part getting consistent phosphate is the biggest thing in a reef tank. Massively stripping phosphate to chase a number is kinda a goal of the past

 

[Randy Holmes-Farley Verified Community Expert]

Lol that spacing mistake made a dirty word that got beeped by r2r!

The filter is pretty aggressive. lol

 

[GiannisK]

Yeah I mean if it was 0.5 steadily I wouldn’t freak out it’s just that it’s continuing to spike.

 

[GiannisK]

RODI water tested at 0.00.

 

[twentyleagues]

What tester are you using? Sorry if I missed it. Obviously you've retested and got the same information? I was going to say source water but I see you have answered that now. As @Randy Holmes-Farley already said the phosphate will eventually reach equilibrium. The dry rock will absorb phosphate in the beginning making you believe you have 0 or very low. But after enough time it will release some based on the concentration in the water eventually reaching equilibrium between rock and water. If you pull it out of the water more will be released and so on until equilibrium is reached. As you feed more you add more phosphate and it starts a new. Dry foods such as pellets and flake and powders usually contain more phosphate then frozen whole foods, mysis and such.

 

[fish farmer]

I don’t have the ULR so it’s possible but it was undetectable with the LR every time I tested, about 10 or 20 times since getting the tester.

I have a Hanna LR as well, usually 0, but I know I have phosphates due to algae growth.

 

[GiannisK]

What tester are you using? Sorry if I missed it. Obviously you've retested and got the same information? I was going to say source water but I see you have answered that now. As @Randy Holmes-Farley already said the phosphate will eventually reach equilibrium. The dry rock will absorb phosphate in the beginning making you believe you have 0 or very low. But after enough time it will release some based on the concentration in the water eventually reaching equilibrium between rock and water. If you pull it out of the water more will be released and so on until equilibrium is reached. As you feed more you add more phosphate and it starts a new. Dry foods such as pellets and flake and powders usually contain more phosphate then frozen whole foods, mysis and such.

This doesn’t really make sense to me. If the water is 0 and the rock is still sucking phosphate up, why would it then release into the water when the water is above 0?

 

[Garf]

This doesn’t really make sense to me. If the water is 0 and the rock is still sucking phosphate up, why would it then release into the water when the water is above 0?

The rocks will be sucking nothing up if the phosphate in the water is truly zero, it will be releasing any bound to the surface.

 

[GiannisK]

The rocks will be sucking nothing up if the phosphate in the water is truly zero, it will be releasing any bound to the surface.

Yes but surely the phosphate wasn’t actually zero, due to waste. It just tested zero because the rock was absorbing it.

 

[Randy Holmes-Farley Verified Community Expert]

Yes but surely the phosphate wasn’t actually zero, due to waste. It just tested zero because the rock was absorbing it.

I'm not sure I really understand what is being debated, but rock will absorb and release in relation to how much is on the rock and how much is in the water.

Regardless of what the rock is doing, organisms not on the rock directly only care about what is in the water, and if it is undetectable, I'd raise it by feeding more or dosing phosphate.

 

[twentyleagues]

This doesn’t really make sense to me. If the water is 0 and the rock is still sucking phosphate up, why would it then release into the water when the water is above 0?

It wont if there is more in the water than in the rock. When your water is 0 the rock will release some of what is in it. This isnt the most scientific way to describe it but it will try to balance "itself". Basically as I understand it the rock has less phosphate than the water the rock will pull from the water. The rock has more phosphate than the water, water will pull from the rock.

 

[Gregg @ ADP]

Dead animals wouldn/t increase phosphate. It'd more likely increase nitrate.

I would add official GFO or SeaChem PhosBond. And switch it out every few days. My phosphate went from .94 last week to .02 today after i kept up what the heck changing out PhosBond

Considering that dead animals are made of phosphate, they would certainly add to phosphate when decomposing.

 

[GiannisK]

It wont if there is more in the water than in the rock. When your water is 0 the rock will release some of what is in it. This isnt the most scientific way to describe it but it will try to balance "itself". Basically as I understand it the rock has less phosphate than the water the rock will pull from the water. The rock has more phosphate than the water, water will pull from the rock.

I'm not sure I really understand what is being debated, but rock will absorb and release in relation to how much is on the rock and how much is in the water.

Regardless of what the rock is doing, organisms not on the rock directly only care about what is in the water, and if it is undetectable, I'd raise it by feeding more or dosing phosphate.

Right I’m not disputing anything here.

I have added the phosguard and will test again soon.

 

[coralboi56]

Considering that dead animals are made of phosphate, they would certainly add to phosphate when decomposing.

From my experience and what I've leaned in classes, dead fish only increase phosphate a tiny amount. If left in the tank, decomposing fish have more of an effect on nitrate. It definitely adds ammonia, but in a cycled tank, the ammonia quickly goes through the nitrogen cycle, eventually adding to nitrate.

 

[Randy Holmes-Farley Verified Community Expert]

From my experience and what I've leaned in classes, dead fish only increase phosphate a tiny amount. If left in the tank, decomposing fish have more of an effect on nitrate. It definitely adds ammonia, but in a cycled tank, the ammonia quickly goes through the nitrogen cycle, eventually adding to nitrate.

I don't think anyone disputes that organisms always contain much more N than P, so when tissue (or food) decomposes, more N is released than P.

However, since the N and P export methods are often decoupled by processes that remove one and not the other, and the fact that reefers care about phosphate at much lower levels than nitrate, the net effects on nitrate and phosphate are challenging to accurately predict.

 

[GiannisK]

Phosphate has dropped to 0.17. I had stopped feeding pellets completely and only fed frozen. I will feed a reduced amount of pellets and combine with frozen from now on. I'll test again in a couple days and see if the phosguard should be replaced.

 

[GiannisK]

Update: phosphate seems to have mostly stabilized. After exhausting the GFO, it’s risen by 0.06 in a week, I’m guessing 0.07 by the time I do the weekly water change tomorrow. Unfortunately it seems I’ll have to do 25% weekly water changes in order to keep it at a steady 0.2, which is still higher than I’d prefer.

My question is, is there a way to lower this without bottoming it out? I’m afraid it’ll be totally gone if I use GFO. I wish I had a refugium or skimmer but I don’t have the space for them. Should I consider carbon dosing?

My coralline algae is also starting to take off, could I count on it taking up a seizable chunk of phosphate? I also want to add a couple more corals, I’m assuming they’d increase the consumption as well.

I can’t cut feeding any more than I have already, but I might try switching even more to frozen (brine shrimp) which I believe have a lot less phosphate than the pellets.