Dwarf Crayfish Dying

[SMiCay]

Could use some encouragement or help! I'm a little discouraged. I had gotten three Alabama dwarf crays from a pretty reliable place (aquaticarts) and over a period of several months they died off. One juvenile male, a young adult male, and a young adult female. The first one to stop appearing was the youngest, I saw what I thought was a molt shell one day but soon realized he must have actually died (maybe a month after I got them). My female had berried for a while and then lost the eggs, and then got a new batch again but suddenly she disappeared about 1 month or so after the first. My older male has just disappeared two weeks ago, and I've confirmed he is definitely gone.

 

They all seemed pretty active until they just disappeared. I never saw my fish harass any of them, plus they have quite a bit of hiding spaces. What could be happening? and I'm afraid to try again since they were pretty expensive. I also just lost a corydora which was sad, I think he just got himself stuck in the shrimp hut thing. But still adds on to the problems.

 

Tankmates: orange rili shrimp (? accidentally got them from the LFS long time ago, breed like crazy and are doing great), dwarf gourami, 4 guppies, 4 corydoras, 5 cardinal tetras, and 2 nerites, and MTS and pond snails.

Tank parameters are always good: 0 ammonia, 0 nitrites, 5-10 nitrates, temp is usually 78*F, we have very hard water and a high pH (in the 8.2-8.4 ish range I think), 29 gallon

 

Tank is pictured below along with one of the crayfish after I first got them. Besides the gourami checking them out the first day he's never appeared to notice or bother them. He loves to eat too much though, little food pig.. 

[xXInkedPhoenixX]

@SMiCay I'm very sorry to hear about your experience and since you were ok with encouragement I thought I'd speak up. I have no experience with crayfish though I used to catch them with a brick, rope and a piece of bacon when I was a kid, catch, play and release. Heh! I looked up your particular type of cray and it seems to me you had a good environment for them, including temp, ph, hardness. It did say they are rather sensitive during molting and tend to get sick or injured during that time (one site recommended very clean water and dissolved aquarium salt when a molt is coming/in progress)- maybe that's what happened as it seemed per your post the deaths or disappearances coincided? What do you think? It also advised they need Iodine in their diet for their molt and even lights stress them out during that time (that's pretty sensitive). The website you got them from said to "avoid bottom dwelling tankmates" not sure if that would mean Corycats, but another website says Corys are fine. Then you had a Cory death? You think he/she just got stuck? Maybe your molting cray got stuck too and mortally injured? Sometimes animals do try and hide when they are ill did you see any signs of potential? Just trying to bounce some ideas around. I like to try and figure things out like that too, to avoid it and see if it's something *I* did- but based on what you wrote it doesn't seem like you are doing anything wrong. 

Edited April 16, 2021 by xXInkedPhoenixX