HCA: Hermit Crab Association

In the over 1-year that I've had these 6 hermit crabs, and the tank having both fresh water and salt water, not once have I seen any of the crabs go near it, dip in it, touch it, gargle their mouth out, yada yada yada.

Is the salt water really necessary?

Yes, it's necessary. They need to balance out their salinity from the water in their shells, and in their bodies.
You shouldn't ever take it away from them.

They might be using it while you aren't watching, because there is about once out of a week that I will see someone by the edge or even in the water.

Yep, like Stella said! If your crabs have been with you for over a year and are still alive, they have definitely been using the sale water even if you haven't seen them in it!

Parroting above, I would continue to offer it to your lil guys. Even though you don't see them using it, its still something you should offer just in case they do use it. Its better to offer anything/everything they need, even if they might not use it in comparison to not offering it and they do need to use it - for whatever reason.

I've only had my crabs for a few months. I've only seen one lean over the freshwater pool to drink. I honestly didn't believe they actually submerge. However...I now have a spycam in the tank. Lo and behold, I caught one going down the ramp of the freshwater pool. Down, down, down. Till I couldn't see his shell anymore. So since they truly submerge, I would guess they also use the saltwater pool.

I have this bigger crab, she's a bit of a clumsy one.
She runs all the way down the tank, and jumps right into the salt pool, simple as that.

StellaCrab wrote:I have this bigger crab, she's a bit of a clumsy one.
She runs all the way down the tank, and jumps right into the salt pool, simple as that.

i have plants in both of my water dishes and almost everyday one of my crabs sits on top of the plants and lets the water bubble on them

Echo what everyone else has said. YES! Thank you for not giving up on them and continuing to give them salt water even though you had your doubts; it has kept them alive!

Research on wild Purple Pinchers shows that they carry briny water in their shells at all times. Where this salt comes from (ie, is it from ocean water or do they excrete it from diet) and how often it needs to replace was not looked into. Each crab has an individual salt level they prefer.

As far as captivity, we see hermits every day that have survived for a long time (decades) without access to saltwater. BUT the issue becomes that no one has tested to see if the ones that survive just happen to be especially hardy individuals. Not having saltwater usually goes hand in hand with not having humidity, heat, substrate, and a well-rounded diet. The outlying crabs that are able to survive might just be lucky. Millions (literally) more have died.

I think it is a beneficial thing to offer since there is zero proof that it isn't needed, and there are no downsides whatsoever to giving them access. Personally, I am not as stringent about saltwater as is recommended and have seen no change in behaviour or deaths. For someone just starting out and on a budget it is not a top of the list item to run out and purchase, but over time it is good to give them so that all bases are covered for safety.