Phosphate Question

[TitanTV]

I know one issue about phosphates is it promotes algea growth. Is it possible to have phosphates in your rock that the algea consumes without having any in the water stream? In other words can you have phosphates and your test kit read zero?

Thanks

[bertoni]

Yes, that's very common. If there's algal growth, there's a phosphorus source, somewhere. The algae could be taking up other forms of phosphorus. Our test kits measure only phosphate, one particular form of the nutrient.

[drcarr]

yes, i just started running GFO to reduce the phosphates. using a media bag in the sump...

[TitanTV]

Thank you for the response

Chrus

[HighlandReefer]

Phosphate is added to your tank water through several sources. Fish foods are the highest in phosphate. Fish excrement can be high in phosphate. These sources add phosphate and the coral, algae & other micro-organisms use it very quickly in a system that reads zero with hobby grade test kits. So as quickly as the phosphate is added then the occupants use it up & you get zero phosphate readings. If your phosphate level is high, then rock and sand can absorb the phosphate and release it back depending on the water phosphate concentration. Using GFO will reduce your phosphate to a zero reading if used correctly.

If you are having problems with algae and/or cyano in a system with a zero phosphate reading, then the best way to approach reduction of phosphate available to them would be to use less fish food & use low phosphate fish foods. Overfed fish simply pass the extra phosphate they don't need out in excrement. Continuing to run GFO in a tank that reads zero can help since phosphate reads around 0.005 ppm in pristine reefs and is well below detectable levels using hobby grade equipment.

[fishchef]

Hanna type meters will help where chemical tests fail. With them you will get a reading that will help define the performance of the GFO. Less guess-work.

[bertoni]

I don't believe that the meters are necessarily any more accurate than a good chemical test kit, although the meters are easier to read.

[Genetics]

TitanTV, is the algae contained to just one rock?