can high po4 kill fish

[jarrett shark]

i wanted to know if high po4 can kill fish?? I am down to only 1 huge sohal tang but he is real hardy and I wanted small fish to add to my tank. My po4 is 2.0 and in the middle of getting it down. I am in the middle of going from fowlr to reef tank. Yes i over feed these aggresive fish when i had them but they are all gone.

[HighlandReefer]

What is your ammonia reading?

[jarrett shark]

0-.05

[jarrett shark]

just think its in the sand bed that i will be removing in the next 4 weeks

[HighlandReefer]

Your rock and sand bed will absorb phosphate proportional to the concentration in your water. With your phosphate level, it will take a while to pull the phosphate out of rock and sand. GFO will work for this, but you will need to replace the GFO weekly until the phosphate level drops below 0.03 ppm.

How is your nitrate?

I would suspect that your ammonia level climbed at one point. Ammonia is very toxic above 0.2 ppm. You are sure your ammonia is between 0 - 0.05 and not 0.5?
Many ammonia kits don't go down to 0.05.

[bertoni]

Phosphate isn't toxic to fish in any tests I've seen. There might be some limit, but it's far above 2 ppm.

I would worry about the ammonia level. It should be undetectable, although failed ammonia kits are fairly common.