Fluval Phosphate & Nitrate

[Ruth]

I have not tried out that product but I am with OCPD on the Fluvals. Canister filters, without almost obsessive maintenance, are IMO nitrate and phosphate factories. I think that for the most part if you gut them of all sponges and media and use for carbon or rowaphos or similar they probably work OK. I have an Eheim canister filter that I run carbon in for a few days a month.