Phosphate/Phosphorous

[Buddy1234]

So, I just had a major outbreak of brown/red algae over a several month period of time. I submitted testing samples to ATI and discovered my silica was high in my RO/DI water. So after replacing the resin in my RO/DI system, many water changes, running biopellets, and carbon the tank is now clean and looking good.

I sent another testing sample to ATI and they came back with Phosphorous being limited and to stop running GFO. My results were Phosphorous 8.64 ug/l vs a recommended level of 14.66 ug/l. Phosphate was 0.03 mg/l vs recommended level of 0.04 mg/l.

I am running biopellets vs GFO(or are they the same). I am concerned if I stop running the biopellets my levels will rise and I will start to get algae again.

My tank is a 70 gallon cadlights with a sump. I am also using a skimmer. Fish are two wrasse, three damsels, one clown, and one banggai cardinal. I feed three cubes(2 frozen brine, 1 frozen mysis) per day.

Thoughts??

 

[Randy Holmes-Farley]

That difference is very small and you may or may not see a difference.

Biopellets don’t do much for phosphate unless they are a type with GFO in them. They are mostly for nitrate.

 

[Buddy1234]

That difference is very small and you may or may not see a difference.

Biopellets don’t do much for phosphate unless they are a type with GFO in them. They are mostly for nitrate.

So the lower Phosphorous/Phosphate levels should not affect my coral growth/condition?

Appreciate your replies

 

[Randy Holmes-Farley]

So the lower Phosphorous/Phosphate levels should not affect my coral growth/condition?

Appreciate your replies

It is hard to to know exactly what phosphate level is optimal, because it will depend on what else the corals are eating, the alk level, pH, and other factors. It is a fine experiment to dose some or feed more and see whether there is a benefit.

 

[Buddy1234]

Calcium was 429 mg/l, alk was 8.92 dkh, PH runs about 8.2 to 8.3, magnesium is 1369 mg/l. Seems all these levels are in a good range. Nitrate was 6.56 mg/l so it seems running biopellets is ok. Not crazy about dosing phosphorous because it is just something more to do and I may overdose. So, maybe just leave it with what I am doing now?

 

[Randy Holmes-Farley]

If corals seem fine, I might do nothing. If they seem pale or slow growing, I’d try more fish food or dosing phosphate.

 

[Buddy1234]

Got it! Thanks again!