Thanks all for the replies!
I'm not so worried about the sand as I have around 10 geophagus and a large L25 that seems to not keep any sand in one place haha. Its also quite deep so it's been helping with bacteria growth I hope, the tank is more than 3 years old as well.
Ill give some more info on the fish though. Its a 180 gallon tank. The stock includes, Gymnothorax Polyurondon (Freshwater tiger moray), Geophagus Red Head Tapajo, Geophagus Winemilleri, Red Severums, Mbu puffer, L25, L114, LDA007, Hoplo catfish, rope fish, pearl gourami, and Congo tetras.
If anyone is worried about the size of the fish, don't worry no one is to large for the tank yet.