Right now they're in a 29g growout (the biggest turtle in there is like 3 inches with their neck extended) with a fluval 306 canister (thankfully that one doesn't get heavy enough to hurt me haha), their big boy pad will be a 110 with a W/D sump. The rid-x is tempting just because they're so freaking dirty that even being small and having a ton of live plants in there I still have to do water changes a minimum of 2x per week. Just not sure because the physiology of a turtle is so different from a fish, and they don't have a slime coat to act as a protective layer... I guess I'm just concerned that the bacteria might eat at their skin since they don't have that additional layer of protection?I love that thread too... amazing that everyone isnt doing it. At first i was strictly doing to help keep the foam pads in the eheim clean and man does it work i kept doing it even with sumps because of all the health benefits rd stated. I dont think it will harm the turtles its basically bacteria spores. Try a little (maybe 1 quater teaspoon ?) then up the dosage to what rd suggests.
Is the turtle tank on a sump or canisters (assuming sumps)