The smaller Volta (bought second) can be seen here more or less well. It is about 8"-10" I'd guess (versus the bigger, first bought, in the 4500 gal that's closer to 18"). It seems to be doing well but it's been a long time since I saw it feed, not because it doesn't but because of the cat-&-eel pile that forms at feeding. Still I somehow think it has not been feeding as well as in the beginning years, never see its tummy bulge.