HCA: Hermit Crab Association

I was wonder as your salt water evaporates do you add more salt water of freshh water becuase salt dosn't evaporate with the water. I have a large salt water pool that is part of the tank so i can't just change all the water

You aren't going to like me much...

You can of course add more fresh water but after one addition you aren't guaranteed that theres enough salt or too much. Either will cause stress. You need to do a big clean in my opinion atlest every 3-4 weeks with the salt water. And what if they put their waste in the water. Mine use my waterfall as a flush toilet.

Our homes aren't filtered like the ocean. It needs to be done.

Don't hit me.

I agree, change it all and be safe!

yep,I fully agree,change it once a day,remove all the old salt water and replace with fresh salt water. Nothing worse than mucky water,even if it is topped up.
If it just evaporates during the day,i wouldn't worry about topping it up,just replace it once a day,because if you just keep topping it up,your crabs will end up with molting deformities/death from over concentrated water. I have had that happen(from bad pet store directions) and there's nothing more upsetting than seeing a hermie stuck in exo and in pain.

Akkk,my crabs are like that too,using the water dishes as their toilets

I forgot to mention that salt water has a filtration system in it. The water never goes bad. I might just be forced to buy one of those salt water reading things(very good english)

Changing a large salt water pool daily is pretty labor intensive. It takes me close to an hour to dig up the pools, clean and dry the gravel in them and put it all back together, there’s no way I have time to do that daily. I change it weekly and generally top the water off with fresh in the middle of the week. Particularly if you have a filter, I think changing it daily is total overkill. If you’re worried about the salt levels get a hydrometer and test the water.

I’ll also note that having salt water that’s a bit too concentrated won’t hurt your crabs as long as you have fresh water. It certainly won’t cause molting deformities or death. Crabs will regulate the salinity of shell water by changing their intake of salt and fresh water. More info: Greenaway, 2003, Terrestrial adaptations in the Anomura Memoirs of Museum Victoria 60(1): 13–26

It wasn't the too strong salt water that killed my crabs when they became stuck in their exos and died?
Wonder what could have done it?

if you feed your crabs commercial food then that might be the problem. theres a preserative called ethoxyquin that really messes a crab up when they molt(most ending in death)

Too weak of salt water can cause moult deformities, but it's not a problem if it's too strong, because they can dilute it with fresh water. In the wild, they usually drink out of tidepools (they don't just walk up to the powerful waves to get a drink!), and usually tidepools are a little concentrated due to evaporation.
I have large filtered pools, too, what I do is top them off daily, either with salt water or fresh, depending what I feel like. Once a week, I siphon most of the water out with an aquarium siphon, then replace the water. Once a month, I take out the whole thing and clean the filters and everything. At least, that's the plan; usually the crabs dump a bunch of substrate in and I have to clean them more often.

Nah,I don't feed any commercial food at all.
But I haven't had any hermies die for quite a while since I started using collected sea water anyway. The salt I was using before was hermit crab salt crystals made up 2 teaspoons in 200mls water or about 7 fluid ounces(pet store directions).
And each crab died when it tried to molt,by either becoming completely stuck in the exo or dropping so many limbs as a result of being stuck that it'd die anyway.
But it's interesting to find out after all this time after believing I had found out what the problem was,that it wasn't the problem at all.
Gee,i was on the wrong track.

Well, I don't know, maybe that was the problem, since we don't have a really good understanding of their preferred salinity, but as long as you also had fresh water, I'll venture to guess that wasn't the problem. And really, 2 teaspoons to 7 ounces isn't terribly strong; the proper mixture is 1 1/2 teaspoons to 8 ounces. Possibly there was something added to the commercial salt? Or something missing from it? At any rate, real ocean water is definitely the best for them, I'm sure your crabbies appreciate it. I just switched to real ocean water (except I live 1500 miles from all salt water sources, so I have to buy it at the pet store ). I hope I can have better crabby health and better moults, too.

Wow,that is food for thought

I think I know what's happened.
Willow,you said 'And really, 2 teaspoons to 7 ounces isn't terribly strong; the proper mixture is 1 1/2 teaspoons to 8 ounces. '
I think the teaspoons I was using were too large(i like big spoons,measures the coffee granules the way i like)
My teaspoons are about 3/4 the size of my tablespoons.
But it may not be the reason at all,I'll never know for certain.

I have to wonder as well whether anything was added to these salt crystals I was using previously such as anticaking agents,etc.
There was no information about the salt crystals on the side of the container,and it was recommended for hermies.