Pump size for TLF reactors with GAC and NP biopellets?

[rzadun]

I had trouble with the pellets. They would tumble well in my zeo reactor, but the filter material I used to stop pellets from escaping would clog with mulm. I switched to a plastic mesh used for needle point that I got at a hobby shop for 98 cents a sheet and cut it to size. No more problems with mulm.