Looking for general recommendations

[stargatedalek]

Newly set up tank and I'm hoping to get some general suggestions on anything in particular that might need changing, or any particular things I should be aware of with this setup. I'm also curious about the risks(?) of too much humidity, can it cause ill effects or is it just going to affect the amount of effort on my part?

What is the volume of your main tank?
20 gallons.

How many hermit crabs do you currently have? How big are they?
None.

What substrate or combination of substrates are you using? How deep is it?
3/4 - 1 inch coconut husk to hold humidity with 2 & 3/4 - 3 inches of sand on top of it (sand is a mixture of crab designated sand and reptile desert sand).

Do you use distilled, bottled, tap or other types of water?
I use tap water with a dechlorinator agent.

If you are using a dechlorinator, what brand is it? Does it state to remove all heavy metals, chlorine and chloramines?
"Nutrafin CHLORXCHANGE" and yes it says chlorine and chloramines.

What brand of sea salt are you using to supply your hermit crabs with salt water?
Funny story, I had some Nutrafin salt sitting around from my old molly tank, and I figured that would work. I went to go find it just now because I couldn't recall the brand, and it wasn't pretty, the salt had caused most of the exterior layer on the cardboard to fall apart, all but obscuring the label. A bit of clumpage (but no more than one would expect in human consumption salt) and no foreign debris. I'm wondering if I should still go ahead with or buy a new box? I wouldn't assume salt would have an expiry date(?).

I have two water dishes set up currently, but haven't used any salt yet.

What heat source are you using and where is it positioned?
I use an overhead light over the front right quarter of the tank (I've heard some nasty things can happen with under-tank heaters if you can't get one with a thermostat, and I assume what's bad for pacman frogs would be bad for burrowing crabs).

Have you calibrated your thermometer(s) and hygrometer so that you can interpret accurate readings?
I use a digital hygrometer and thermometer.

What is the air temperature range and humidity inside the tank?
23 - 27 Celsius. I try to keep the humidity between 70-80% but it may sometimes drop into the late 60's during the course of the day if I'm away for a few hours and I have over-misted a few times with it going into the 90's.

What is the highest temperature that the substrate near the heat source reaches?
27 Celsius.

Do you have any photos of your tank or hermit crab(s) of concern? If yes, please attach them to your post.
Not pictured I have a tiny beta tank (just a little plastic thing, poor hypothetical betas) as a quarantine. The idea being that if a crab needs to be separated the quarantine can be placed inside the main tank.

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[emmac350]

Can you post a link to the 'hermit crab sand' brand you're using? Some of them aren't safe for crabs.

I'd recommend a new box of salt - no telling what the box might have leached into your salt. Plus it'll be hard to break that clump up and get accurate amounts to mix for your crabs.

I'm glad to see that you're doing your research and getting things set up before you get your crabs - we don't see many people doing this much before bringing home their crabs. Thank you for taking the time to ensure your crabs are as comfortable as they can be!

[Ginger]

Hi stargatedalek, welcome - I didn't get a chance to say previously! In addition to emmacs comments, I've seen reptile sand that also has odd unnamed bits and bobs in it that I would avoid. I think your best bet would be aquarium or play sand. Regarding the salt, I'm 99% sure that you are discussing a salt that would be used to create a brackish environment for freshwater water fish or to help treat a diseased tank. This type of salt is more often than not inappropriate for hermit crabs as it is not full strength (this is what is generally recommended, please correct me if wrong). With the under tank heater usually they are used on the side of the tank rather than actually under it to avoid burning burrowed crabs. When above ground it is not them that need worrying about it, is the ceramic heat emitters that are the culprits. And lastly, I would consider calibrating your thermometer - my digital one that I recieved reads 6% above what it should.

[stargatedalek]

Thank you both.

The sand is by Crab Worx and reptile sand is by Nat Geo. I cleaned and strained the sand to remove dust and foreign particles before adding it to the tank.

The sand is for hatching brine shrimp, but upon going back today to buy sponges I couldn't find any other kinds of salt (just other brands).

I got an analogue thermometer today to cover both ends of the tank, so I guess I'll calibrate them both.