What do i need to get for my red eared slider How big tank

what do i need? how big tank?

I'm sure you know this answer RES but I will answer for the benefit of those who do not know lol.

1.You need the biggest tank you can afford upfront. A good rule of thumb is 10g per inch of shell, so no a 10g would not be fine unless you have a 1in hatchling, but it won't last you long so it doesn't make sense to buy small. Red Ear's can easily grow 12 in or more with proper care! If you can't afford a large tank, there are other options, a kiddie pool, a preformed pond liner, a rubber maid tote etc. Turtle tanks / the side cut out is a waste of money. Also Sliders like deep water so fill the tank!

2. You need a UVA/UVB light the box must say UVB and it must emit at least 5% UVB but 10% is best.

3. You need a Heat/Basking lamp, this can be a clamp lamp from a hardware store for 5 bucks and a household bulb.

4. You need a Basking spot. This needs to be a place for the turtle to come completly out of the water to dry off and sun himself. You can use a log, a platform, a dock, a ramp, etc as long as the turtle can fit on it comfortably.

5. You need good filtration. Turtles are messy. Shoot for 2x the gallon size but more is good too. For example if you have a 40g get a filter made for an 80g or bigger.

6. Submersible heater. Depending on where you live, you may need a heater, the water temps should be mid to high 70's if you cannot achieve this w/out a heater, then get one.