Thought I'd share my lazy method of brackish water. I've been using it on Diamondback Terrapins for a while now and have been making out just fine.

Basically I use one and a half cups of salt (12oz) per ten gallons of water.

This normally (if I check it with a hydrometer) gives me between 1.012 and 1.014SG. My current hydrometer is pretty cruddy however so I often don't bother.

As for the salt I've been using Morton's pickling salt (the one in the green box). It comes in even bigger and cheaper boxes than kosher salt, and has absolutely nothing else in it besides salt.

Nice idea..comments?

Whoa, can't believe I missed this thread.

Comments? Yup.

The biggest problem is that generic food-grade salts are almost totally, or are totally, sodium chloride. Marine salt has a much higher percentage of magnesium chloride, around 20% IIRC. Not to mention the percentages of sulfur, calcium, phosphorous and trace elements missing from grocery salts. I'll admit I've never tried saint's method, and I'm sure it's adequate for tougher species, but I'd be wary of using this mix on more delicate brackish species.

WYite

Well like I said in my original post, I use it for DBTs. They're essentially brackish red ear sliders. They got sturdy pretty well covered.

I do wonder just what minerals and trace elements most brackish water fish *really* need. The jade sleeper goby did find in brackish originally with a smaller DBT for a while using the pickling salt, then in with the monos using I think Instant Ocean brand mix (I don't remember I swiped half a bag from someone I know who does salty) and it did just as fine in pure freshwater.

One thing that I never realized before we got to talking about it the one time, was how much hard water affects something like that as well. When I was trying to ID some pretty purple algae that was growing in the feeder guppy tank, the only thing that had changed recently was adding a pvc elbow (for the fish to swim in) that had been taken from a salt water tank. Either Wyite or MC (can't remember who got it first) traced it down to a nuisance algae that's very common for saltwater tanks.

Before then, (when this post was from) I never really looked into it, but had always thought that saltwater/brackish animals while wanting or in some cases I'm sure needing other minerals and elements, NaCl was numero uno required for continued long term living.