Can hermit crabs differentiate salt water from fresh water?

[lilohermies]

I have 4 water sources in my tank: 3 freshwater pools and 1 saltwater pool. As i've witnessed, crabs seem to drink by lifing their claws like a spoon to their mouths. Last night, I saw one of my crabs sitting by the salt water pool lifing his claw and drinking the salt water. It may sound a little mean, but I panicked, and immediately picked him and put him close to the fresh water pool. He climed up the rock and started drinking the fresh water now. I'm concerned: can he tell the salt water apart from the fresh water? I didn't think hermit crabs could drink fresh water... I have 3 other fresh water pools in my tank that are all dechlorinated, changed twice a day, easily accesible, easy to climb out of, and have sponges. I hope he's not having trouble finding them. I would take the salt water pool out, but from my understanding, they need it to submerge in, especially before a molt.

Can anybody help? Is this natural? Is he just wetting his gills and preparing for a molt? Am I doing something wrong with the water? Is he derranged? Will the salt water harm him? Should I get rid of the salt water pool entirely?

Thanks, :)
I'd appreciate any advice.

[Wai]

They drink from either one regularly and this is perfectly normal. Hermit crabs store water inside their shells of a particularly salinity. They mix the fresh and salt water together until their shell water is of ideal salinity to them.

Species that live further inland (e.g. indos) are more able to distinguish the odours of fresh water and salt water than species that live closer to the ocean (e.g. straws).

[ladybug15057]

I'm concerned: can he tell the salt water apart from the fresh water?

If a true ocean/sea mix is used, yes they can tell the difference if it is mixed correctly. (which would be the 1.021-1.024 salinity level) Using the HBH salt mix (or the other salts sold for hermies) when tested they did not register on the hydrometer at all. So there is a chance it would be hard for the hermies to determine between the 2.
Some who have adopted hermies who the previous crabbers used the salts sold for hermies noted that when they got them home and settled in the hermies definitely consumed a good bit of the 'real' ocean water mix when introduced to it.
I know of a crabber who had an escapee and he put an ocean water pond on the floor along the wall with a fan blowing. He found his hermie this way, as though the hermie was able to smell the ocean water and headed towards it.
What brand of ocean/sea mix do you use, and how do you mix it? (ratio of water to mix?)

[lilohermies]

I actually used pre-mixed salt water that comes in a water bottle. It's from Petco and it's called salt water glub. Is that okay?

Thanks for all the help by the way!

[ladybug15057]

Sorry, but the glub water is also misleading and does/did not test out to the 1.021-1.024. It should be one sold specifically for salt water fish tanks.
In the Crab Care section, under "Recommended" should be used.
http://www.hermitcrabparadise.com/crabc ... r/salt.php

[lilohermies]

Thanks! I'll definately get some Instant Ocean tomorrow. So for the salt water glub? Is it harmful to my crabs?

[Wai]

If you have Instant Ocean, there's absolutely no reason to use the glub. Get a refund for it if you can.

[ladybug15057]

If you're asking has there been any scientific testing to show for a fact whether it is harmful/safe, no not that I know of. But one thing... it doesn't do them any good, they need the elements/minerals found in ocean/sea water.

Wai, could the glub salt water be added to the not recommended list too please?

glub

Heck for the price of this and all the longer it would last the other ocean/sea mixes for salt water fish would last about 7 months longer...

[Wai]

*Sigh* more dodgy products to add to the list...

I wish people would stop making placebo products like those...