I will give my advice in bold, below.
1. What kind of substrate is used in your tank and how deep is it?
20g and 10g tank connected. In the 20g it is coconut fiber, deepest end is 6in. In the 10g it is playsand only a couple inches deep.
Curly - Sub should be at least 6 inches through the whole set up, or three times as deep as your largest crab - whichever is deeper. It should be moist enough to hold it's shape (sand castle consistency) but not so wet that water pools in the bottom. Many of us use a mix of 5 parts play sand to 1 part coco fiber - it holds shape and moisture well, and helps with humidity.
2. Do you have gauges in the tank to measure temperature and humidity? If so, where are they located and what temperature and humidity do they usually read?
Yes two gauges, one in each tank. The cocofiber side is located just offset from the middle, right above the substrate. It's usual readings are 75-83F temp and humidity stays right around 75. The sand side is in the middle exactly, again temp stays right around 80 and the humidity drops a little lower at times but stays above 70 most of the time.
3. Is a heat source used in the tank? If so, what?
Cocofiber side has a 100w red infrared floodlight and sand side has a 100w night spotlight.
4. What types of water are available (fresh or salt) and how is the water treated (what brands of dechlorinator or salt mix and what ratio is used to mix it)?
We have two pools, one salt and one fresh. The brand for both that we use is All Living Things. For freshwater it takes 4 drops per 8 fluid ounces and for the salt it takes 1tsp per 8 fluid ounces. There is also and airstone in the freshwater pool (which they love).
Curly - Unfortunately, many products marketed for crabs aren't appropriate. You need a dechlorinator that removes everything (LOL, like Prime, and you need marine salt like Instant Ocean to get the proper minerals. Here is the care sheet that explains it better than I can:
viewtopic.php?f=127&t=92553
5. What kinds of food do you feed and how often is it replaced?
We always give them hermit crab fruit salad, sun dried red shrimp, dried coconut, and then red hermit crab color enhancer made by Fluker's Hermit Headquarters which is a mixture of dried carrots, dried red bell peppers, dried cherries, and salt. On occasion we will give them some fresh cut up fruit and fresh rivershrimp in a can. Yesterday we gave them fresh mango and I also got them a cuddle bone. We probably don't replace it as much as we should, longest time between changes can get up to 4 or 5 days unless we give them something fresh then no more than a day.
Curly - It's okay to leave dried food in longer than fresh. Mold doesn't harm the crabs, it's only a problem for allergic humans. They do need protein and calcium daily.
6. How long have you had the crab and what species is it, if known?
It gets a little hard to remember because we have a good amount, but two of them I would say about 2 months and the other one only about a month. Two of them I'm pretty sure are purple pinches and the other one I'm not sure about, it has always been very red.
7. Has your crab molted, and how long ago did it happen?
Out of the two that molted today the smaller one molted once before which was a little longer than a month ago which is weird because I thought it took a lot longer between molts, but he is also a tiny crab (his name is also Tiny!). Then the one that molted the other day had never molted until then.
8. What type of housing are the crabs kept in, what size is it and what kind of lid is on the housing?
So we have a 20 gallon and 10 gallon glass aquarium side by side connected by a tunnel made of craft mesh. Both have a grated cover that is entirely covered by tinfoil and taped down except for some areas on each side to allow for more air to get it.
Curly - If you have trouble with humidity, it is fine to seal the top completely - they will get air exchange when you go in to change food and water.
9. How many crabs are in the tank and about how large are they?
We currently have 19 crabs ranging from about half an inch big to our biggest which is about an inch and a quarter. 5 big, 6 medium, and 8 small.
Curly - You have too many crabs for your space. Here is the HCA guide for crab sizes/ tank sizes/ how many can go in a tank:
viewtopic.php?f=26&t=92541
10. How many extra shells are usually kept in the tank, if any?
There are currently 12 extra shells in the tank, plus another probably 15 that we have to swap out every so often.
Curly - HCA recommends 3-5 extra shells per crab. There are correct and incorrect shells to buy. Here is the shell guide:
viewtopic.php?f=24&t=92552
11. Have there been any fumes or chemicals near the crabitat recently?
No.
12. How often do you clean the tank and how?
Once a month we do a full change of substrate and change the things in the tank around.
Curly - When you have proper substrate, you do not need to change the sub unless there is an emergency such as a bacterial bloom or flood.
13. Are sponges used in the water dish? If so, how are they cleaned?
No.
14. Has anything new been added to your crabitat recently?
No.
15. Is there any other information you would like to share that might be helpful (anything that is regularly part of your crab care, playtime, bathing, etc.)?
Nothing that has been recently, occasionally we will take them out to hold them or give them a bath but it has been a long while.
Curly - Crabs carry a mix of fresh and salt water in their shells. Bathing them can interrupt this. New crabs can be dipped in the water so they smell like the tank when they are added, but otherwise bathing is not recommended.
16. Please describe the emergency situation in detail.
Today we had two crabs that surface molted and one of them lost his big claw and a leg somewhere in the process, when we found him he was by two others crabs and the limbs that were detached seemed to be a bit crushed in some areas. The other one that surface molted seemed to be entirely fine and had no missing limbs but another crab had started to eat their shed exoskeleton. Also the other day, maybe 4 days ago at most we had another surface molter and when we found him, some other crabs were starting to surround him. All three of them we ended up carefully moving and burying them with their exoskeleton. We have never had one molt on the surface in the past, and that's out of 8 others molts from other crabs since our first. The only other issue we have had in the past with molting which happened months ago is we had one lose a leg and another one had lost their small claw, and those were both while they were burrowed.
Curly - I believe a big part of your problem is over crowding. And not enough sub. Surface molting is not normal. If a crab surface molts, it must be isolated from the other crabs, or they will kill it. If a crab surface molted , DO NOT re-bury it. Crabs make a cave to molt, and re-burying them will suffocate them. You need to carefully dig them up, and if they are alive, they need to be isolated with ideal conditions and their exo so they can eat it. I'm not sure that you have enough space to isolate them in your tank with a 2L pop bottle cut down and lid off; otherwise you need to set up an isolation tank where they can recover and be kept separate from each other and the other crabs. Improper sub can cause problems with molts, such as missing or deformed limbs. If conditions are proper, they can re-grow them with their next molt.
Also thank you for the template, I wish I knew where to find it so I could fill it out right away as I've used this site for information before but I didn't know where to look for it.