ok so i was thinking about trying a sand sifting star (small one) for my 40B but i think this tank would be too small for it, also i have Seaflor substrate. now having said that i have notice that there are different size grain seaflor, mine are not the big pieces, they are the grain size just a little bigger than my regular agra alive sand i have in my other tank(just for reference i bought it in 15# bags at petsmart). so i guess my real question is can a goby sift this? any other creatures that can?