Sorry didn't clarify on that, it's a 25 watt red bulb that is used to keep temps from going under 65. We've had a really cold winter here in NC and I keep it handy for them. I swap out the all substrate twice a year, plus I "fluff" it several times also. It's seeded with spring tails and pill bugs. It's layered with hydroton, charcoal and eco earth mixed with an organic potting soil. Come spring I'm going to redo the tank with a drilled bottom, I'm switching all vivs over to this. All other toads are doing great.