u/Hyperfixaction

Hello! I have a around 15 year old red eared slider who I’ve had since I was little in a huge tank with basking, suction cone rocks, ping pong balls, a scrubber (that never stays on) and lettuce floating ball enrichment, but I feel like there’s something more I want to do. I switch up the food from time to time for enrichment and move around the rocks certain ways but is there anything else? Some people ik take their turtles out of the tank but my turtle hates it. Whenever he needs to be out for whatever reason he stays in his shell the whole time or one time he even hissed. I don’t know if he would like to play outside or his tank and I’m too scared to stress him out bc I wanna make him happy. Is there anything else I can do? If it’s item wise, a link would be great too!