Fiddlers with hermits success story from LHC

[MudCrabDude]

Neat!

I would keep that consistency as well for land hermits, as long as there is a separate saltwater pool/dish handy at all times when they need to fill up the molt sac.

Oh, and here is a bit more information about land (non-hermit) crabs, the blue Florida Cardisoma sp. crab, that can also be applied to fiddlers when making their habitats at your personal place (with the fiddler habitat much more "shoreline"-type):

Habitats:
Adults utilize a range of habitats and tolerate a wide range of salinities. Blue land crabs are limited to areas where they can burrow to intersect the water table and maintain a 1-2 liter pool in the bottom of the burrow. Thus they are functionally limited to areas where the water table is within approximately 7 feet of the surface. Competition for optimum shoreline burrows may be the force that drives terrestrial crabs to migrate to inland areas.

http://www.sms.si.edu/irlfieldguide/Cardis_guanhu.htm

Hopefully the information from this website is up-to-date...

[JediMasterThrash]

I guess I totally misunderstood what you were saying.

My whole substrate isn't dry right now, just the surface. The lower substrate stays moist because of the water splashing out of the pools, plus the sand goes in sand-castle moist, and it never gets a chance to fully evaporate.

The only time i have sand dry all the way to the bottom is over the UTH side of my 10g ISO, and crabs never bury down on that side.

So the question is what level of saturation. Slightly moist, moist on the lower half, but possibly dry at the surface, or moist all the way to the top, which usually means there's saturation and pooling water at the bottom.

That's what I think might cuase problems. The pooling water near the bottom, without filtration, can build up high ammonia, and there's no circulation or sunlight to keep the bacteria in check.

Crabs are more than capable of wetting the surface to get the digging started, and it pro bably does need to be moist once they drop down a few inches to continue.

Do fiddlers absolutely need to molt in pooled water within a burrow? Or will they be able to molt in just a moist burrow, or in the water itself?

[MudCrabDude]

Do fiddlers absolutely need to molt in pooled water within a burrow? Or will they be able to molt in just a moist burrow, or in the water itself?

From personal experience, pooled water within a burrow. Although I've read other keepers online that theirs molted in freshwater aquariums.

Moist burrows? I'm not sure with fiddlers.

Anyway, yeah, the problems you mentioned about chemical buildup without proper circulation inherent in a small closed system is an issue.
I've tried for years experimenting on setups that are "relatively small and affordable" - I'm always thinking of ways of proper circulation and filtration for small-time hobbyists without resorting to 100+gallon setups, hehehehe! Pretty much failed most of the time (ie. not one setup lasted over 9 months - always ended up spending more on ruined filters, saturated tank setups, moving entire colonies due to leaks, buying more tanks, electric wires of submersible filters being chewed, etc.) but I'm always on the lookout for gizmos and gadgets that I can rig, even if it's not directly intended for tank maintenance.

Off topic, I've hated seeing moon crabs/fiddler crabs/mini crabs/Thai crabs die in mid-molt (ex. you see the shell halfway opened). *Sighs*...However, someone in arachnoboards(dot)com have had a successful filtered setup, though it is large 50/50 tank (half wet, half dry)and uses gravel (yep, gravel). Burying is pretty much out of the equation as the setup only requires one land crab per tank, so the crab will not be disturbed/eaten during molting, I think. If more than one crab is present, I think he kept it in a really large tank 55 + I think....

[JediMasterThrash]

I wanted to create a setup that would have saturated water at the bottom, and would filter it. I was thinking of using undergravel aquarium filters underneath the substrate, and then keeping it saturated/pooled in the lower inch. And the water would be pumped from the bottom and flow back onto the surface of the substrate, and get reabsorbed back down to the bottom.

But I can't figure out how to actaully make that work. Undergravel filters won't pump water up 6 inches above water level, since they just use airstones to create water pressure.

And if you tried to use any other kind of filter, how would you keep it from getting crammed up with sand and FB?

The only way I'veseen it done successfully was to have a sloping beach into a pool, and then the lower part of the substrate, below water level, is saturated of course, but since the open water has a filter, and usually runs a waterfaul up to the higher level to circulate the water, then it can work.

But I don't want to give up half of my 92g tank for a big pool. If I had like a 180g that was longer, then I could do it.

[MudCrabDude]

I wanted to create a setup that would have saturated water at the bottom, and would filter it. I was thinking of using undergravel aquarium filters underneath the substrate, and then keeping it saturated/pooled in the lower inch. And the water would be pumped from the bottom and flow back onto the surface of the substrate, and get reabsorbed back down to the bottom.

But I can't figure out how to actaully make that work. Undergravel filters won't pump water up 6 inches above water level, since they just use airstones to create water pressure.

And if you tried to use any other kind of filter, how would you keep it from getting crammed up with sand and FB?

The only way I'veseen it done successfully was to have a sloping beach into a pool, and then the lower part of the substrate, below water level, is saturated of course, but since the open water has a filter, and usually runs a waterfaul up to the higher level to circulate the water, then it can work.

But I don't want to give up half of my 92g tank for a big pool. If I had like a 180g that was longer, then I could do it.

Yup, I agree with everything you posted.

In the 90's I've even tried using crushed and ripped and ground toilet paper as am experimental substrate, I kid you not. That is definitely not recommended...yikes....hahahaha. Other times, I tried just having no substrate but large coarse rocks that formed makeshift "caves" so there would be no need for burying as there were plenty of "hiding places" provided....... Oh well....

[Mamakins]

Regarding the pooling water, I just did a deep clean of my 30g. The only reason I did a complete substrate change was because I could see how wet and yucky the sand on the bottom was. As I removed the sand, it was kind of stinky too. When I put new sand in, I did not wet it right away. After just a few hours, I was able to poke a hole with my finger and it did not collapse. By the next day, I could already see dampness when I looked at the bottom of the tank. In less than 3 days, I'd say 80 -90% of the bottom of the tank was damp. The coco fiber side did not have this problem of getting soggy on the bottom. The water dishes are on the sand side, but the sand side is twice the side of the forest bedding side. I used to have the one water dish on each side and still, did not have a soggy substrate problem with the cocobedding. I think, my 70g when set up will be mostly coco bedding with just a small 'beach' area. When I redo my 30g for my little guys, I think I will switch to all cocobedding