buying things to eat snails is all very well, but it takes up stocking room, and alters the tank, plus you end up with the problem of what to do with them afterwards. assasain snails are good, but on a tank that size you will need a massive group and then they breed, so you are back to square 1. i have 1 assasain snail in my 4x2x2 and i did a lovely job, never saw any pest snails, but once it eats them all you have to keep feeding them!
i like having a few snails in my tank as they are THE SINGLE BEST thing for your substrate. they turn it over, releasing any trapped gas pockets before they build up too much, and also eat any left over foods, and with cichlids, thats a massive boost!
other options to consider are.. manually removing the ones you see, or crush them up as fish will eat them. feeding less, or putting cucumber in as suggested.
they normally arrive on things like plants (hece i was mine thoroghly), but will only thrive if there is tons of stuff for them to eat.
if you rid yourself of the snails, get some corries, as they do a similar job, eating the left over food, but look nice and are very sociable..provided your cichlids arent the mega aggressive ones!
snails should be seen in a different light if you ask me, they do far more good than bad and are an excellent indicator of how much you are over feeding. remember little and often, dont let it all get to the substrate levels.
