Crab died mysteriously, need help identifying cause and what to do!

[Hedoor]

1. What kind of substrate is used in your tank and how deep is it?
Play sand from Home Depot and eco earth mix ~1:6

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, they are located on the center back wall, they are the analog Zoomed ones. They usually read 80*f temp and around 75% humidity, I am trying to raise it but the lid is about an inch to short.

3. Is a heat source used in the tank? If so, what?
There are two heating pads on the back of the tank, covering about 70% of the back of the tank.

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)?
I have both fresh and salt water that I replace weekly, I treat them with Reptisafe instant water conditioner and Instant ocean sea salt for the water. The bowls are both embedded in the sand and about 1.5-2 inches deep with aquarium rocks on the bottom to act as a ramp

5. What kinds of food do you feed and how often is it replaced?
I give them cooked frozen shrimp frozen organic bell peppers with every meal, they also get a fruit, usually apple, blueberry or raspberry and a veggie usually broccoli and misc. kitchen herbs leftover from cooking. All Organic. Replaced every other day.

6. How long have you had the crab and what species is it, if known?
I've had them for about 4-5 months, PP

7. Has your crab molted, and how long ago did it happen?
I am unsure, they went under for about a month right after I bought them.

8. What type of housing are the crabs kept in, what size is it and what kind of lid is on the housing?
They are kept in what I believe is a 29 gallon tank, it uses one of those glass lids that fold and have a plastic bit to cover extra out front.

9. How many crabs are in the tank and about how large are they?
3 crabs total, now 2. they are all fairly small, about the size of a ping pong ball.
Krill and Rangoon have been with me for about 5-4 months
Flamin' Hot Cheeto, the largest, has been with me for about 4 months, they were last seen last night, scampering about.

10. How many extra shells are usually kept in the tank, if any?
Around 5 extra shells scared about

11. Have there been any fumes or chemicals near the crabitat recently?
None.

12. How often do you clean the tank and how?
I clean their water once a week on the weekend other than that I mist the sides of the tank.

13. Are sponges used in the water dish? If so, how are they cleaned?
None.

14. Has anything new been added to your crabitat recently?
They switched tanks around 3 weeks ago from a 10 gallon to the 29 gallon. All new decor from Hobby Lobby and a new hide made from one of those hole filled crates and a length of fake vine woven in. Along with other little fake plants, a small hamster disk, and moss pit.

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.)?
Krill, my sweet baby, had buried themself shell and all and refused to come up for 2 weeks, so I had to dig them out as the new tank would suffer without the old tanks heating pad, they buried themselves as soon as they got in the new tank.

Rangoon, was also acting strange, after the tanks switch they sat in the corner of the tank right up next to the heating pad and refused to go anywhere else. I knew they were alive because when I misted the tank they moved a little. Eventually I put a piece of apple next to them to try and encourage eating, the next day when I went to check the apple was in his shell and he was nowhere to be found.

I am not sure which crab has died, as I hadn't seen either for about 1.5 weeks before today and there was not shell with them which makes me think it was Rangoon.

16. Please describe the emergency situation in detail.
One of my crabs died under mysterious circumstances. When I found them, they were halfway out from under the water bowl, and up against the glass. There were little red/orange specks around them that I assume where mites, they were about the size of a small grain of rice. They were already beginning to rot and had some maggots of them. I dug them out along with the sand around them. I put them in a little coffin and they will be getting cremated tonight.

Please help, I don't want my other crabs to get hurt.

[curlysister]

1. What kind of substrate is used in your tank and how deep is it?
Play sand from Home Depot and eco earth mix ~1:6

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, they are located on the center back wall, they are the analog Zoomed ones. They usually read 80*f temp and around 75% humidity, I am trying to raise it but the lid is about an inch to short.
Curly - Your temp and humidity are just fime.

3. Is a heat source used in the tank? If so, what?
There are two heating pads on the back of the tank, covering about 70% of the back of the tank.

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)?
I have both fresh and salt water that I replace weekly, I treat them with Reptisafe instant water conditioner and Instant ocean sea salt for the water. The bowls are both embedded in the sand and about 1.5-2 inches deep with aquarium rocks on the bottom to act as a ramp

5. What kinds of food do you feed and how often is it replaced?
I give them cooked frozen shrimp frozen organic bell peppers with every meal, they also get a fruit, usually apple, blueberry or raspberry and a veggie usually broccoli and misc. kitchen herbs leftover from cooking. All Organic. Replaced every other day.
Curly - Crabs do well with a variety of foods. Meats, grains, greens, fruits, veggies, leaves, nuts, seeds, eggs and egg shells, dried bugs, cuttle bone, etc. They need animal protein and calcium daily.

6. How long have you had the crab and what species is it, if known?
I've had them for about 4-5 months, PP

7. Has your crab molted, and how long ago did it happen?
I am unsure, they went under for about a month right after I bought them.

8. What type of housing are the crabs kept in, what size is it and what kind of lid is on the housing?
They are kept in what I believe is a 29 gallon tank, it uses one of those glass lids that fold and have a plastic bit to cover extra out front.

9. How many crabs are in the tank and about how large are they?
3 crabs total, now 2. they are all fairly small, about the size of a ping pong ball.
Krill and Rangoon have been with me for about 5-4 months
Flamin' Hot Cheeto, the largest, has been with me for about 4 months, they were last seen last night, scampering about.

10. How many extra shells are usually kept in the tank, if any?
Around 5 extra shells scared about
Curly - HCA recommends 3-5 extra shells per crab. For 3 crabs, that would be 9-15 extra shells. Check the 'shells' care sheet to see that you have appropriate types of shells.

11. Have there been any fumes or chemicals near the crabitat recently?
None.

12. How often do you clean the tank and how?
I clean their water once a week on the weekend other than that I mist the sides of the tank.

13. Are sponges used in the water dish? If so, how are they cleaned?
None.

14. Has anything new been added to your crabitat recently?
They switched tanks around 3 weeks ago from a 10 gallon to the 29 gallon. All new decor from Hobby Lobby and a new hide made from one of those hole filled crates and a length of fake vine woven in. Along with other little fake plants, a small hamster disk, and moss pit.

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.)?
Krill, my sweet baby, had buried themself shell and all and refused to come up for 2 weeks, so I had to dig them out as the new tank would suffer without the old tanks heating pad, they buried themselves as soon as they got in the new tank.

Rangoon, was also acting strange, after the tanks switch they sat in the corner of the tank right up next to the heating pad and refused to go anywhere else. I knew they were alive because when I misted the tank they moved a little. Eventually I put a piece of apple next to them to try and encourage eating, the next day when I went to check the apple was in his shell and he was nowhere to be found.

I am not sure which crab has died, as I hadn't seen either for about 1.5 weeks before today and there was not shell with them which makes me think it was Rangoon.

16. Please describe the emergency situation in detail.
One of my crabs died under mysterious circumstances. When I found them, they were halfway out from under the water bowl, and up against the glass. There were little red/orange specks around them that I assume where mites, they were about the size of a small grain of rice. They were already beginning to rot and had some maggots of them. I dug them out along with the sand around them. I put them in a little coffin and they will be getting cremated tonight.

Please help, I don't want my other crabs to get hurt.
Curly - Is this the same situation as you posted about a month ago? You thought that the other crabs had dragged Rangoon's shell up to the surface, and there was no sign of Rangoon. There was no mention in that post about him not moving and putting the apple next to him, you said he was underground?

[Hedoor]

Its a different situation than a few months ago, Rangoon decided to show up on the surface about a week or two after that, I apologize for not replying to that with an update, I'm new to using any forums. This only began happening after I switched tanks ~two weeks ago.
I'm worried that maybe there are mites in the tank because of the red/orange rice things, but my crabs aren't very happy about being handled so its hard for me to check as they just retreat all the way in their shells.

[curlysister]

The mites won't be causing trouble with your crabs. The mites will have been in the tank already, likely you never noticed them.