Need help ASAP understanding crab behavior

[Motörcrab]

I'll try to run through a few things with your crabitat you will want to try an improve on. Your 5:1 mix of sand to coconut fiber is a good start. It should be sand castle consistency. Depending on how big your crabs are the HCA recommends the substrate to be 3 times deeper than the size of your largest crab, or minimum of 6 inches. whatever is greater. deeper substrate will lower the risk of another crab digging up a molting crab for an easy snack.

Your temperature is on low side. 74 is considered the minimum temperature. Most of us try to keep our tank around 80. I believe you may not have enough heating pads to get your temperature high enough. You have two 9 watt pads. I believe they are probably 8x8" each. You want as much heating as you can on the rear of the tank. If your heating mats are able to be insulated (double check what kind you have, some can't be insulated and can pose a big fire risk) you can cover the entire back with Reflectix, foam insulation, or cardboard wrapped in aluminum foil. The heater should cover from the top of the substrate to the top of the tank and the entire length. Your low temperature could be mainly be due to your screen lid on the tank. You are doing the right thing with adding towels and place mats. You can also cover the entire top with plastic wrap. The crabs won't suffocate due to opening the tank to change foods and waters. Don't use the plastic wrap with the heat bulbs it will melt. Adding a blanket on top will help hold in heat too. I prefer glass lids over other types. My guess is the heat bulbs are drying out your sub resulting in your frequent misting. With a few tweaks to the top you may be able to limit your daily misting. Smaller tanks usually require more work to maintain proper temperature and humidity especially in the winter.

As for your water bowls. What type do you have? Most of us use plastic food containers that are deep enough for your crabs to fully submerge. We also nest one container in the other to prevent leaks and the lower container stays in the tank all the time. the bottom container also acts as a barrier if a crab decides to molt next to or under the container. Add a layer of stones to the bottom container, it makes it easier to pull the top one out to change the waters. As for worrying about the small crab getting out. You can pick up plastic canvas, crafting mesh, at craft stores. It is plastic sheets that have tiny holes. You can cut it to form ladders in and out of the pools. We have baby crabs with shells the size of a dime and they climb it no problem! The leaking could just be your crabs going in the water and spilling it, or possibly filling their shells too. It can also be evaporating due to the heat lamps too. That could be why your humidity is ok. With thinking you have a water leak I would try to dig down in a small area near the front of the tank to see if there is water build up on the bottom. If you do find an a layer of water let us know ASAP.

Be careful what foods you are purchasing at any stores. They generally have preservatives and other additives that are not good for crabs. I try to avoid anything that I can't pronounce and isn't single ingredient items. I stick to crickets, grasshoppers, mealworms, krill, anchovies, and so on.

All of us went through the same things as you when we first started out taking care of crabs. I read the care sheets on here over and over learning what I could before officially joining the HCA. The best advice I can give is to read through the care sheets then reread them. They are very helpful and are available 24-7. Just about everything is touched on one way or another in all of the guides. I still refer to them for information.

Here is a link to the care sheets.
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