Posted: Fri Nov 23, 2018 10:32 am Re: Suggestions for docks
Being a male at 5" may be close to adult size. Most males only get 6-8" depending on it's DNA with a few getting 9".
The 40 gallon ( regular or breeder type ) are 36" long and 15-18" wide depending on style. For a 5" turtle you may really want to think about filling it all the way and make an "ATBA". That's a small tank for him. Slider's love to swim as much as bask. More water also helps a lot to control your waters parameters. Not many options with only 40 gallon tank and a 5" turtle. A good adult tank size would be a 90 gallon tank with about 50 gallons of water in it ( to prevent escape) and a floating dock. . Then as he grows to full adult size just add more water with a "ATBA".
A simple plexiglass wall around top of tank ("ATBA") , fill full 40 gallons water may be only option to really get a larger ( different) basking area with varying temp for him. See under habitat indoor at basking pic's for some ideas. Also photo gallery too.
Natural cork is easiest could cut a large piece and wedge it between the glass . Even put together smaller pieces of cork to make a longer dock for more room. Turtles need large homes and glass tanks even used cost a lot. Ever think about a stock tank for an upgrade ( 1/4th the cost of glass tanks) can do and offer so much more with the larger widths room. In photo gallery look at Piggley's pic's to see what can be done with one. He's a male RES at 5" too in a 150 gallon stock tank (3'x5') with about 120 gallons water in it.