HCA: Hermit Crab Association

Howdy all!

I was wondering what the best salt water mix is for Hermits? I see that many are using instant ocean, however I found this article stating that there is high levels of certain metals including copper. Now I'm worried to use it. The article link is below. Thanks!!!

http://www.reefkeeping.com/issues/2003-03/rs/feature/

Instant Ocean has been used for well over a decade with hermits and has been shown to be safe. The article you pulled up is 14 years old, and I'm sure the formulations have been tweaked since then.

Personally, I lean towards Red Sea as being a little better, but it's hard to find and more expensive, and there's no proof that it is actually better. Incidentally, I've been using IO alone the past few years.

Probably the best idea would be to have a few different mixes and rotate through then, since each has its own problem of too much and too little. I used to do that with my fiddler's, swap between IO and Kents. Seemed to work really well, but the cost ads up and salt doesn't keep forever since it absorbs moisture and the moisture oxidizes the lesser elements changing the mix in the process.

Hermits do need to have copper in their diets. Whereas you and I have iron in our blood, hermits have copper. Just as humans can (and do, it's a leading cause of poisoning in kids who get ahold of chewable vitamins) die from ingesting too much iron, hermits will die from too much copper. But like how we turn anemic without enough iron, it's harmful for hermits to not get enough. There is a fine line between too much and too little, but for them sea water is a natural source.

Thanks for the quick reply and all the info! From keeping marine inverts long ago, I know copper can be deadly to them and I wasn't aware that Hermits were not as sensitive to copper, (in proper amounts ) That's great to hear that IO is safe, since it's all my local pet shop carries. I will certainly order other brands and switch it up, which makes perfect sense to offer variety. Also I never thought that salt would expire...but good to know for sure!

Thanks so much for putting my worries at rest!