HCA: Hermit Crab Association

I'm new to crabbing and have read a tonne on here so I thought I understood the proper way to prepare the salt water. I also read that its ok to leave the water for a few days before changing it, but my saltwater develops a kind of white scum on top after a day. It looks like salt flakes are separating or something. I use two cups dechlorinated water to one tbsp Instant Ocean. Is that the right ratio? What should I do about the white scum?

I don't know about the scum, but one thing is that I found it very convenient to prepare a gallon of saltwater and a gallon of freshwater in milk gallon jugs. It is easier to prepare, just 1/2 cup of salt per gallon.

Also, if you prefer preparing in smaller quantities,

Hermit Crab Association wrote:Instant Ocean
package indicates to use 1/2 cup (which=8 TBSP) per gallon.
1 1/2 tsp per 8 oz (1 cup) water
1 TBSP per 16 oz (1 pint)
2 TBSP per 32 oz (1 quart)
4 TBSP per 64 oz (1/2 gallon)
8 TBSP per 128 oz (1 gallon)

Sorry I couldn't help about the SW. I think I [possibly] might have that two, there is usually no dirt or sign of my crabs having visited the dish except a tiny bit of white stuff on the surface....

It will scum over. In salt aquariums, a skimmer is used to remove it on a constant basis, but with the crabs it's not harmful and the bowls get changed often enough that it doesn't become a problem. If you can get something to shake the water in when mixing it, it should help to prevent the separation.

That answers my question! Thanks! I was worried it was something harmful. I'll try mixing my salt water in a bottle and shake it.