Strange/bad smell?

[CrabbySquirrel]

I noticed a strange smell in the crabitat recently....it's not strong or anything, it just smells "off". I haven't had a crab die (fingers crossed), so I don't know what that smells like--but I've heard it described as pretty bad, so I don't think it's that....

What other sorts of things can make your crabitat just smell bad?

[CallaLily]

Hidden spoiled food, mold, molting crabs can have a smell usually described as chemical-like though sometimes described as fishy, bacterial blooms smell like rotten eggs but are usually only noticed when digging.

[CrabbySquirrel]

Can you get bacterial bloom with a false bottom? What exactly is it?

I do have one molter right now, and it's my largest crab, so that might be it. I could also take a closer look inside the tank with the lids off and see if anything else shows up...

[CallaLily]

I'm not good at explaining things like this so I'll just quote Wodesorel.

A bacterial bloom in the substrate is caused by anaerobic bacteria which can only grow in places that have a lack of oxygen, and are usually also dark, wet and moist. This bacteria creates a toxic gas (methane) and also acid, which will lower the pH of the surrounding substrate.

A false bottom will certainly help lower the risk I think, as will giving the substrate a good mix now and then when you can.

You really likely wouldn't smell one on the surface unless the substrate was recently disturbed.

[thermidor]

In my tank if there is any smell it is always a piece of dried shrimp that has been stashed somewhere; I remove it, and smell goes away.