I started running bio pellets on my 77 just before christmas.My nitrate levels were not too bad, but phosphates were fairly high.( I use tap water treated with prime for top off and WC's)I had alot of HA and a cyano problem.Just checked my tank parameters a couple days ago, and my phos and nitrate are at undetectable levels.HA is only on 1 rock now and cyano is gone.(I did cut back on lighting for a couple weeks to help)
I give the pellets 2 thunbs up... so far
I just use LR rubble in my sump