How can I lower the hardness of the water in my fish tank?

Question

I have a 30 gallon Malawi cichlid tank and recently put crushed coral in my tank. The water is way too hard. I took some more of the coral out to see if it was that I had too much in the tank and it still continues to be about 350. Some pet stores say theres nothing I can do and others say they have something that will only temporarily solve the problem. I know that cichlids like hard water but I need to lower it just a bit.What should I do?

I have 3 cichlids in the tank.

I have three malawi cichlids in a 30 gallon tank..is that too small?

Answer 1

Well, crushed coral can be good for a high pH and hardwater tank, but not in that amount. But if you had 6.5 pH tapwater and wanted to keep tanganyikan cichlids, you could add crushed coral to your substrate to increase pH and hardness.

Anyhoo, I answered your other post so here is my response again:

Hardness is tough to bring down! It's easy to bring up, as you know, but decreasing it is nearly impossible.

Remove the crushed coral. If you want to use sand, use silica sand, sand blasting sand or pool filter sand. Eventually, as you do water changes, the hardness and pH will go down.

Otherwise, filter your water through peatmoss. Boil some peatmoss so it sinks and it in your filter box. It's not a miracle fix but it might help.

Other products like pH down (pH and water hardness are directly related, btw) are ineffective. They may bring down the hardness temporarily, but hard water has a high buffering capacity. So in a couple days, the water will be just as hard as it used to be.

Oh, how many fish do you have in there? I am concerned that 30 gallons is pretty small for malawi cichlids.

Answer 2

Although Malawi water actually isn't that hard (about 100 or even less) I do need to agree with the previous poster - trying to fight your water will only cause instability and the best thing you can do for the fish is leave it - they'll do fine. Reduce the amount of CC you use in your tank, and otherwise leave it be. A lot of people enjoy playing chemist, but in truth most fish, especially Malawis, are very adaptbable to water conditions, and the most important thing about water is stability.

Answer 3

There is no need to lower your hardness in that tank, the Malawi cichlids love it. 350 ppm total hardness is just right, but it could be higher for them.

The tank may be too small depending on the species and the amount of rocks.

Answer 4

Crushed coral is designed for saltwater aquariums ONLY. It is made of prmiarily limestone which is a water hardener and A PH Raiser. Best bet is to remove the crsuhed coral. You will spend a forutne in PH down. Remove this limestone based product and place natural gravel

Answer 5

Well crushed coral does raise the pH. but the water you starteed out with might also be the cause.
I find that adding a little peat moss to the filter or under the gravel helps to lower it.
You could try peat moss.