RES water volume?

Question
I bought two RED. They are very small. They are about 2" less than 3" and would like to know around how old they are? I didn't know anything about turtles till I got them cause I wasn't planning to keep them. Now I want to take good care of them. My question is how deep does the water have to be since I don't know how old they are? I've been doing some research and it seems that when they are babies they can drown if the water is not shallow enough. Also my filter won't be able to reach the water if I keep it shallow. It would probably reach if I feel it half way up. My concern is, are my turtle big enough to swim with a large volume of water?

Answer
Your research is a little flawed- the idea that baby turtles can drown is actually very old and very wrong. They DO need good basking sites, but they can swim just fine from birth- after all, in the wild, if they were forced to stay close to shore, they would be easily eaten.

They sound like they are about 6-12 months old as a guess.

A great site for care is http://www.austinsturtlepage.com

Http://www.redearslider.com is good as well.