I have had this now about 7 inch Pod eater for a couple years now....... Here is a copy and paste about their pitfalls I posted a while back......Also A recent shot of him going for another scoop!!!!! Someone said maybe get 2, that would be one too many of the little Roto-Tillers
If it needs to be a fish, to clean up substrate, one choice would be a Diamond Goby (aka) Rotor-tiller fish) if you want to have spotless substrate. Many folks use this guy. But they have many downfalls too.
The issues with them are they tend to be jumpers ( no issues with mine) quiet home no kids anymore to startle him with noise. Also a nearly 50 gallon fuge feeding the little pod eater. I have seen where they are tide poll skippers. As long as they have food in this "little tide pool" I think they do not tend to try to leave the pool (jump out of your tank) But it your tank runs out of pods etc , carpet surfing 101 seems to be their next class in school.
The do eat just about anything in the substrate (pods included) leaving the substrate barren of seeable critters. Next, they will rearrange the landscaping of your substrate regularly!! If you have a "DSB" he will make mountains out of it in places. Other than these issues, they are just about unbeatable at keeping the substrate clean, but you pay the cost of living with these issues forever more. Plus they are a neat fish to watch work......... Good Luck.... Warren