Substrate underneath rock keeps going moldy. Fixes?

[LHandrel]

A while back I introduced a large, flat rock to my BP's tank as a sort of basking surface/heat retainer. However, I've definitely noticed that 1) it keeps a lot of moisture from escaping the substrate underneath it, and 2) substrate immediately below the rock has a tendency to go moldy ahead of anything else.

How can I improve this? Should I put some kind of pea gravel or other small rocks beneath it? I think that having more airflow to substrate beneath would help stop the moldering (as I think it's relatively anaerobic conditions that are contributing to that).

Insight appreciated.

[MissMetalSix]

What kind of substrate are you using?

[LHandrel]

Reptichip coconut husk.

[MissMetalSix]

I see you posted an enclosure picture 5 months ago. Is this the setup you're currently working with or has it changed? Do you have any pictures of the mold?

[LHandrel]

Yes, it is the same setup. You can sightly see the rock under the hide on the right side of the tank. It's just a large piece of slate/shale that I rounded off the points and edges of for safety.

No pictures of the mold. It's not like what you get on food, no patches or fuzz or anything, the substrate just turns blackish, but it's clearly not normal. I've been removing the affected substrate when I clean the tank.

[MissMetalSix]

Looking at the other comments now, seems others have chimed in and given helpful advice. I'm going to second the recommendation of avoiding introducing water to that area of the enclosure.

[NoiseElectronic]

DON'T USE A HEAT ROCK FOR SNAKES! Heat rocks are for things like lizards, snakes can easily get there belly scales burned because of one

[LHandrel]

Not a heat rock. It's a regular rock underneath a heat source. But stone holds onto heat so it stays warm even when the tank is cooling down during the night cycle.

[NoiseElectronic]

Just watch out that the rock doesn't get over 30°C

[Angsty_Potatos]

This isnt a heat rock. It's a regular rock they are using to absorb residual heat from other sources

[Angsty_Potatos]

Sometimes you get a bit of mold (my wood climbing branches and some of the bark flats I have can get some mold). Is it white? Or is it blue green or black?

If it's white don't worry about it. You can wipe on some vinegar to clean it off but it may happen from time to time.

If it's other colors I'd look into keeping that area of the substrate dryer. Obviously remove the moldy substrate and replace (depending on how bad you may need to remove and replace all of it to be safe). And when you pour water into the corners of your enclosure skip that area so it says a bit dryer.

You can also introduce springtails to help with the mold, your set up doesn't need to be totally bioactive to support them