Increasing water hardness for crawfish? Or changing diet for

[Craw Chief]

Hey everyone,

The water in my area is extremely soft (like 1 dGH/30 ppm GH), but crawfish require hard water (I'd be happy with anything over 7 dGH). I've read quite a bit online about increasing water hardness. So far I've added Epsom salt and an iodine supplement in the prescribed doses I've seen online: Tablespoon Epsom salt per 10 gallons and 1/2 the dosage of Kent Marine Iodine supplement.

Some say the easiest is simply to add crushed coral or limestone. However, the pH in my tank is around 7.5-8, which from what I've read, means those things will not dissolve very well.

Others say to purchase Marine salt and add that to the tank at 1 teaspoon per 10 gallons. If that's the case, what brand of salt should I be looking for? Just go down to Petco and get their store brand of marine salt or what?

There are also some liquid calcium supplements such as Kent Marine Liquid Calcium. I'm assuming I could add that at half the dosage they prescribe (since I'm keeping fresh not salt water).

I'm just looking for some more concrete advice. I like to have specific instructions; i.e., "Go to the store, buy this product, add this much, and the hardness will increase by such-and-such amount."

Essentially, I just want to ensure that the crawfish is getting a sufficient amount of calcium. At present, his diet consists of algae wafers and spinach. Is it possible for the water to be soft and yet provide a sufficient amount of calcium to the crawfish through his diet? Should I modify his diet in any way?

I've seen other people online feed their inverts (like snails and shrimp) Ken's Premium Veggie Sticks with Calcium ( http://www.kensfish.com/moreinfo/ken...s-calcium.html ). I'm considering purchasing that due to the good reviews it's received from other invertebrate keepers.

I appreciate any and all advice you can provide! Thank you!

[davidjh2]

You can buy a PH raising additive, I used to use one until I realized how hard my water was.

[Craw Chief]

I think my pH is fine though. I'm concerned more about the GH. Someone on another forum suggested I add crushed oyster shells to slowly add calcium to the water. My concern is that the pH would be too alkaline (7.6+) to allow for the shells to dissolve effectively.

[gaylorddaniel]

Your PH is fine. Also you are correct, at your PH limestone will not go into solution very rapidly. I am a crayfish farmer with very soft well water and find that Calcium Chloride is the most soluble form of calcium and immediately will harden water. As you know crayfish need calcium to harden their shell. Water hardness is measured in terms of CACO3. (Calcium Carbonate) Hardness depends mostly on calcium content and to a lesser degree of magnesium hardness. If you find a liquid water hardness product, i expect it should work well.

Cheers,

Gaylord Daniel

[Craw Chief]

Hey thank you for the advice!

Since my last post, I've been using Kent Marine Liquid Calcium and Seachem Replenish with some success! I also added crushed oyster shells, which I'm not sure are having an effect or not considering the high pH.

Thanks again!