potential uth blistering and sub moisture + humidity questions

[mylittlecrabs]

i have had a tikaton uth on the side of my tank and it has been fine (as far as i know) except that its drying out my substrate. i use a mix of play sand and coco fiber. i never thought that it was blistering but i think it might be. i did try to pull it off so i could move it up (i need to add a bit more substrate anyways but have been holding off because im not sure where one of my crabs is buried) and some of the adhesive was sticking to the tank and not coming off so i stopped and put it back on. im worried that the parts without the adhesive are going to be a problem. i think i may have attached the adhesive wrong when i got it. the heat inside has been at 80 degrees.

a piece of wood at the bottom but it isnt touching the glass its just the angle of the image.
heres the product https://a.co/d/azKkO8X
i have been misting the substrate by it a lot but it just keeps drying out. and i dont know if i should pour a bit of water at the corner as i have seen other people recommend because i have the 2 water bowls at other corners and the sub at the bottom is wet. the glass above the waters and the front of my tank have a lot of condensation, enough that it occasionally forms water droplets. ive used a pencil in the sub thats against the wet glass to test if it holds a tunnel and it does. they have actually stayed there for a few days.

im sorry this post is kind of long but im just worried. any advice would be appreciated.

[Jlmills525]

Is your UTH above or even with the sub? It should not overlap, that will dry it out.

You can also use moss or a layer of leaf litter over the sub to hold the moisture into it.

[mylittlecrabs]

its almost even i put it too low so i was trying to move it ip

[Jlmills525]

i have heard that a layer of leaf litter can help with sub moisture. I've also heard that the top layer (not sure how deep) is ok to get dryer as long as they can get past that to the moist stuff for tunneling

[hermitsinnc]

The adhesive on the heater you have is not reusable. If you try to move it (any more than you already have) it will be a fire hazard (and could be already. Make sure there is nothing highly flammable back there.)

I see that you had a substrate that was mostly EE: is that the current conditions? Because that will impact how your sub holds moisture.

Since you aren't sure where your molter is buried, pouring water in a corner may be a bad idea as they like to dig in corners and you don't want to flood its tunnel.

[mylittlecrabs]

thank you hermitsinnc, i have added in a bit more of the play sand since then (probably like just 1/3 cup) but am scared to do too much because of the tunneler. but it is mostly EE yes.

[mylittlecrabs]

and jlmills525, i might have to try the leaf litter out. thanks for the advice! and its just dry on the very top and i didnt think about how it would be okay if they could just get right to the moist part lol

[curlysister]

It is normal for the top bit of substrate to be dry, as long as the lower layers have enough moisture that it will hold it's shape for crabs to make tunnels and caves. My UTH's go below the level of the substrate, so I just add a bit of water there now and then. But if you can tell with the 'pencil test' that it is moist enough further down, don't add more water or you risk a flood.
Agree that the sitcky UTH's can't be taken off and re-positioned. I'm not sure what to say about the bubbling of it.
You can add substrate while crabs are down, just don't drop it in or pack it down.