Posted: Thu Mar 11, 2010 1:06 pm
The gravel "vacuums" for fish poop don't work properly for turtle poop because it is typically heavier than the gravel and the vacuums are too weak, even when broken up. I've had two RES turtles for 14 years and I did away with gravel around year four. I've consulted with several vets over the years and they all recommend doing away with gravel for the sake of your turtle's health (they will eat it, and re-eat it, and re-eat it...) and for the improved water quality.
If you want the tank to look nice, I would suggest river rocks if your turtles are small enough that they won't move them around and crack the glass. Once they get full-size you will benefit from having no rocks at all, or flat rocks from a rock quarry lining the base, but the turtles really don't care as long as they have some climbing/basking areas.