what sort of turtles are they?
I go with bare tanks for my turtles (mud and sliders) and a powerful Fluval 350 external canister filter.
be aware depending on the species, a 50 gallon tank is woefully inadequate, particularly for females. Large softshells can hit 2' in carapace length. Big snappers can hit 50 lbs in weight. Some map and painted turtles get rather large too. Even big red ear slider females can get well over a foot (males substaintially smaller, more like 6-9").
Ugly people have sex all the time. We wouldn't have 6 and a half billion humans if you had to be beautiful to get laid.