Zeovit + Bio Pellets

[Delphinus]

I'd say yes to both unfortunately. Carbon does its own thing and isn't replaceable by pellets or zeo, although is space was a concern you don't really HAVE to run carbon in a reactor, a filter bag passive in the sump in a high flow area can work well apparently.

I found the pellets were awesome on their own for reducing nitrates, but did not do much for phosphates, and if I ever did pellets on their own again I'd still run GFO alongside. I think they do reduce phosphate to an extent but at a much slower rate than they reduce nitrate.