How Do I Make Brackish Water?

Hi all, I'm brand new here, so new I haven't even had a chance to fill out my profile yet. I did a search on yahoo on "making brackish water" and it brought me here, now I just need the answer. :)

I am making a tank for my fiddler crabs who, my research shows, would prefer brackish water. Yet, I can't for the life of me find a "recipe" for making it. I bought a bag of marine salt (Ocean I think was the brand). I bought the smallest bag because (mostly because it was the cheapest) none of them said how to make brackish water only "mix contents with ## gallons of water" and I don't need that much water - not anywhere near it. My tank is sand on the bottom with a "beach" at the end and only a couple of inches of water. So I was thinking if someone could tell me a per gallon ratio. I do not have a hydrometer (is that the right name) nor do I currently have the funds to buy one.

I would appreciate any help. Thanks!
 
Get a hydromemer. Best bet. They run around $5-15, I think. That will measure your specific gravity. I make low end brackish, about 1.007 sg, by mixing about a cup to a cup and a half of salt per 10 gallons of water.... so that would be.... let's see.... 20-25 tablespoons per 10 gallons, which would be around 2 tablespoons per gallon. I think. It's hard to say, I use a hydrometer.... but I'll get a gallon of water and some salt and use my hydrometer to see. Two flat tablespoons/gallon gets the sg from 1.000 to about 1.005, I think. So I'd use three tablespoons/gallon, and get a hydrometer ASAP
 
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As suggested by Liz, get a hydrometer. They are not too expensive and are betting than using a rough guide. That said, I don't know if fiddler crabs are sensitive to salinity changes but I'd still recommend knowing your water parameters. Congrats on doing the research :thm: It looks to be an interesting tank.
 
One tablespoon per gallon gets me to about 1.005 SG these days, but initially it was about a tablespoon and a third to get to 1.005. Instant ocean makes a plastic hydrometer that's around $10 and it's really necessary. Your water in your tank will become more brackish as some is lost to evaporation, so if you keep putting in exactly the same amount of salt eventually your SG will creep up. Hydrometers are a necessity, because you'll eventually use less salt than you do at first to make water at the right salinity.

Eric
 
Well, thank you guys. When I first found the forum and posted my quick question my baby was crying to get up from bed so I didn't have time to search the forum. Then after he was settled I came back and searched and found the sticky post on FAQ's (along with the jokes that maybe it will help reduce the newbie questions on "how much salt..." - boy was I embarrased). But thank you for your gentle answers which I am sure y'all have probably answered a hundred times by now. :)

I will see if I can find a hydrometer but where would I even look to buy one? It will have to be VERY inexpensive for me to get one right now. Otherwise, I may just go in on the very low end of your estimate, Liz , and gradually introduce it to these guys.

I was sold one crab as an alternative to ghost shrimp which I have had before (I should have known better and done my research first, but I do get impatient sometimes). The LFS sells them as freshwater pets. :( Bad, bad. Everything that I've read about them says they prefer brackish water (and that they need to get out of the water a lot), which makes total sense now that I remember seeing them at lowtide when visiting the ocean.

So I bought another cheapy ten gallon tank and put in sand and rocks and some live plants and bought my little "Lazarus" (he likes to play dead) a friend and named her "Mary". So now all I need to do is make the switch to brackish and these guys should be in seventh heaven. :)
 
YOu can find the plastic hydrometers at the chain pet stores. (petsmart and petco) I forget the actual cost, but I think mine was about six bucks or so. You could also probably find one at www.bigalsonline.com .

Emily
 
fishiechick said:
Well, thank you guys. When I first found the forum and posted my quick question my baby was crying to get up from bed so I didn't have time to search the forum. Then after he was settled I came back and searched and found the sticky post on FAQ's (along with the jokes that maybe it will help reduce the newbie questions on "how much salt..." - boy was I embarrased). But thank you for your gentle answers which I am sure y'all have probably answered a hundred times by now. :)

I will see if I can find a hydrometer but where would I even look to buy one? It will have to be VERY inexpensive for me to get one right now. Otherwise, I may just go in on the very low end of your estimate, Liz , and gradually introduce it to these guys.

I was sold one crab as an alternative to ghost shrimp which I have had before (I should have known better and done my research first, but I do get impatient sometimes). The LFS sells them as freshwater pets. :( Bad, bad. Everything that I've read about them says they prefer brackish water (and that they need to get out of the water a lot), which makes total sense now that I remember seeing them at lowtide when visiting the ocean.

So I bought another cheapy ten gallon tank and put in sand and rocks and some live plants and bought my little "Lazarus" (he likes to play dead) a friend and named her "Mary". So now all I need to do is make the switch to brackish and these guys should be in seventh heaven. :)


Looking at other people's guides, maybe mine was off. The slower you introduce to brackish, the better, for fish atleast. I'm sure it won't hurt crabs to go slowly as well. It is generally suggested to go by .002 increments, so until you can get a hold of a hydrometer, if you are eager to start the conversion to brackish, use the smallest amount of salt you can, like maybe 1/2 to 1 tablespoon per gallon, just to hold them over until you can get a hydrometer. Make sure the salt is dissolved in some dechlorinated water before adding it to the tank.

It would probably be cheaper to go up to a LFS (one that carries saltwater stock would probably be more likely to carry one, I'd guess) and pick up a hydrometer, that way you don't have to pay extra for shipping. Make sure the hydrometer you get has the full scale of specific gravity, from 1.000 up, in as small of increments as possible. Mine typically goes in increments of about .004, I think. My mom has some "deep six" hydrometer that only measures marine water, so I had to run out and buy a different one.

If the plants you speak of are aquatic, not too many plants do well in brackish water. A list can be found here
Personally, I have some Vallisneria that seems to be doing well in my lower end brackish tank.
 
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Thanks! I mixed up a teaspoon of the salt with nearly a gallon of water to start them off, I also just added some to their tank so it should be a very gradual change for them. I only had the live plants in their tank to start them as I'm growing a bunch from bulbs for my other tanks. Now that I'm to the point where I'm adding the salt water and they look to be doing well, I'm going to exchange them with the fake plants from another tank. The crabs should like them better anyway as they will give them yet another thing to climb (the live plants were to small). The crabs seem to like their new place. :)
 
A teaspoon of salt (hopefully you are using marine salt) will do nothing to make BW. To raise your SG (measured by your hydrometer) by .002, it will roughly take a little under 1/2 cup of salt/5gal.
 
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