Phosphate OK?

[Spridle]

Is a reading of 0.4 mg/l OK for phosphate level for a reef tank? I tried a phosguard pad for a few days and the reading is still the same. Tank seems to be doing good.

[Geoff]

what kind of test kit are you using? a lot of the inexpensive ones are not nearly accurate enough when you get into that range. phosphates are also a hard thing to test for. depending on the phosphate compounds it test for it may not be giving you an accurate reading anyway.

G~

[Spridle]

I use a SeaTest kit that costs $13.99 for 20 tests.

[Spridle]

I read the directions on the SeaTest phosphate kit again and it does not say what the acceptable PO4 should be. Since 0.4 mg/l is the 2nd to lowest on the color scale, I assume this is an OK phosphate level. Any opinions on at what level PO4 should become a concern?

[rockyboy]

0.03ppm - Good

0.10ppm - Critical

0.25ppm - Coral growth retarded

0.50ppm -

The above from Salifert test kit

IMO, I prefer to use rowaphos. It absorbs phospate better than phosguard.

[Spridle]

Thanks Rockyboy, that's helpful. Does anyone know how to convert mg/l to ppm for phosphate?