Ideal water depth

[ral]

I am going to migrate my Betta from a 1.25 Gallon jar to a 5 gallon tank. The tank is several inches taller than the jar. What is the ideal water depth for a Betta.

TIA

 

[Seahorse]

Well I have two betta's all by their lonely selves in standard 10 and 12 gallon tanks. I just make sure to leave an inch and a half at the top alone because they are air breathers.