Extremely high phosphate

[stinkydavis]

Was any of the dry rock previously used in an aquarium? Do you know the phosphates of the tank the live rock came from?

I don’t. I bought it all from a LFS with a good rep in the area.

 

[Spare time]

I don’t. I bought it all from a LFS with a good rep in the area.

It wouldn't hurt to ask. I'd also see if they can double check your phosphate with another kit since 10ppm would be an incredible number to achieve

 

[stinkydavis]

my first though is that it is very doubtful. When you say you use API test I doubt it even more. I would suggest to get a different brand of test kit. Maybe also post a pic of your tank, a tank pic always explains a million words.

 

[stinkydavis]

Could this be the cause.Should Ireplace?

 

[PlumbTuckered]

I do regular water changes. I did not know about breaking down the canister weekly and will do that tonight.

Canister filters are Phosphate and Nitrate factories.