I think Thor is doing fine THANKFULLY (or my daughter would hate me forever). He's basking, and eating some turtle treats (chopped up water snail and dried shrimp), but he's not very social, well he's never been very social

you can see him hiding in the one picture.
Thor has a Marineland C-220 canister filter, the inlet cover now in place is the stock one that looks like an upside down bird cage, picture. The other inlet device is the PVC tubing, picture. Physics says in order for there to be an even flow (sucking in this case) the holes must be graduated in size, kind of like what you see in overhead A/C systems. The hole size ratio is dependent on the length between the holes. So I did the math, and came up with the hole sizes shown. Obviously what I did not account for was that Thor could stick his head into the largest opening, duh me! I should have thunk that he'd try and stick his head in there soon or later. So I guess I could redo the math using a smaller sized largest intake hole, or I could affix some bars (maybe just one) over the opening, so he can't do that again.
The gray PVC pipe is the outlet, picture, and it's angled to break the water surface between 6 and 8 inches depending on the water level.
I guess what I'm wondering is if there is a commercially made intake apparatus that other RES owners use, or I could just modify mine?
hey one other question, we pulled Thor out of the creek as a hatchling a little larger than a quarter two and a half years ago. He's now about 2.5 inches in shell length from front to back. Is that kind of small for a 2.5 year old RES ?. We DON'T want him to outgrow his tank! but I'm also abit concerned if he's healthy at that size, or are we unintentionally feeding him too little. He does get a VERY diverse diet of plants and aquatic critters, and worms (his favorite), and monthly water cleaning, and water level checked on daily.
thanks for your thoughts!!!
Todd