The Puffer Forum

What I would do is go with a very, very fine gravel. It is lighter than sand so it doesn't compact, looks very nice and the fish can still easily burrow in it.

I found that at a local store, they sell it by the 50lb bag. Its perfect for things like this.

I also have a sand substrate (play sand) planted tank and the crypts seem to love the sand. But it makes me nervous (its a shell dweller tank and if they dig and hit a bad patch...) and I'll probably change it out one of these days.

Standard blasting 'sand' (aka 'grit') around here is - if remember the numbers right - 2-3mm particle size, sitting exactly on the sand-gravel boundry. It should not compact as finer grades will do, so should have better diffusion. That is finer than my substrates, but should be safer than real sands.

Myaj - what kind of shellies do you have in? If they're multis or simis, my experience is they'll never have an issue as they were the most productive bulldozers I've ever kept. Brevis in contrast, just don't get move enough sand and I did move them to a coarse/gravelish aragonite.

Eric

Mine are brevis, and they rarely do more than dig a little bit of a "basin" or fan some sand into their shells.

I plan to move them to another tank soon anyways, and will use the fine gravel at that point.

I wasn't aware that onyx would compact. My suvatti tank is mainly onyx but has about 20% eco complete mixed in. I got to say that I prefer the eco for plant growth. I was thinking about going pure onyx for when I transfer it to the 55g, now I'm not so sure.