Every slider sold is a hatchling the size of a quarter. Every slider that survives is a dinner plate. The tank you buy for the first one is wrong for the second, and most keepers find this out by watching the turtle stop growing in water it has outgrown.
The rule
Ten gallons of water for every inch of shell. Not tank capacity: water. A slider at 4 inches needs 40 gallons; a 10-inch female needs 100. Round up, because the number is a floor.
Water depth should be at least one and a half times the shell length so the turtle can right itself if it flips. Depth matters more than people expect, and a wide, shallow pool is worse than a deep one of the same volume.
What that looks like
| Shell length | Water needed | Common tank |
|---|---|---|
| 2 to 4 in | 20 to 40 gal | 40-gallon breeder |
| 5 to 7 in | 50 to 75 gal | 75-gallon aquarium |
| 8 to 12 in | 80 to 125 gal | 125-gallon or stock tank |
Cheaper ways to get there
- A 100-gallon plastic stock tank from a farm store costs a third of a glass aquarium and will not crack. Build a wooden surround if you want it to look like furniture.
- A pond liner in a wooden frame holds any volume you like for the cost of the liner.
- An outdoor pond, where the climate allows, is the best home a slider can have and costs little to dig.
What else the tank needs
A dock the whole turtle can climb onto and dry off completely, a basking lamp over it reaching 90 to 95°F on the surface, a UVB tube beside the lamp, a heater behind a guard holding the water at 75 to 80°F, and a canister filter rated for two to three times the water volume. The Slider starter kit in the shop lists all of it with sample prices.
