Old vs New Sand

[tyronepines]

Hello, I recently rehomed a couple axolotls and I plan on moving my hermit crabs to their bigger tank once I finish cleaning it out. My question is, can I reuse the old sand in the axolotl tank for my hermit crabs if I wash it? I'll have to buy new sand either way to make sure it's deep enough for molting but also it seems like a waste just to throw all this sand out? I'm not sure if bacteria or anything will be an issue for the crabs. If nobody knows for sure then I'll just throw it out because I'd rather be safe than sorry.
Also might as well ask this while I'm here as well lol. The tank I had for my axolotls was an open tank aquarium and I just cannot find a lid that will fit anywhere. I saw that sometimes people will wrap their tank with plastic wrap to keep the tank humid, though usually with a lid as well. Do you think it would work without the lid, as long as I make sure there is nothing high enough for them to try and climb out on? I plan to eventually get some plexiglass or something similar cut to size, this would be a temporary solution.
Thank you in advance!

[curlysister]

I don't have an answer about the sand, sorry, hopefully someone else will chime in.

My first two tanks when my crabs were tiny (10 gallon and 20 gallon) did not have lids, and I used plastic wrap on them for a few years, no problems!

[hermitsssss]

IF there is bacteril blooms, it will stink, if its not deep enough to molt, you can add more sand to the old sand, thats what i do sometimes, anyway

because the same was used in the axolotle tank- (i think) you will need to dry it bc its probably very wet, but as long as it does not sting, is not dyed, or have any chemicals it should be safe