A UV light is not required with amphibians. If you want a light, use a "Repti-Glo 2.0" CFL bulb or similar 2.0 bulb, this is all you need, otherwise most other bulbs arn't good for the toad.
Yes, make sure you cover the gravel, with at the very least 3" of substrate.
The ratio of land to water sounds good, but how deep is the water? Southern toads are not like FBT's, there abilty to swim in comparison is poor, all it needs, is again, a maximum of 1 toad's depth of water. If you have deep water, it could easily drown.
Looking foward to the photos!
~Royce![]()