How to raise KH

Add crushed coral but that will raise ph too,kh and ph usually work hand in hand.

Don't worry,i assure you people with more knowledge about ph and related issues will answer your question.I know little about ph and related,all i know is kh is carbonate hardness,hard to achieve high kh with plants since plants take in carbon

http://www.aquariacentral.com/forums/showthread.php?s=&threadid=1390&highlight=crushed+coral

hi, i think this might help.....

Cheapest and fastest way would be to use Baking Soda.

Use a 5g bucket ... fill it with your tap water. Then conduct some experiments on the 5g bucket w/ Baking Soda to see how it alters your KH and pH. Apply what was learned from the 5g bucket to your tanks volume.

I've never found baking soda to have very lasting effects, at least not when used by itself.

In low KH situations, it is correct that a strong increase in KH can drive up pH. The trick is to boost KH just enough to provide buffering (resistance against pH change) while not raising pH any more than absolutely necessary.

I would recommend you get some crushed coral. You won't need much- a cup at max, I would think. Start by putting a tablespoon or two in filter bag (a clean nylon stocking would work, too). After tying off the bag, place it in your filter. As the coral slowly dissolves, KH will gradually rise. This can take a week or two, so don't expect anything overnight. You'll need to monitor pH and KH. When KH reaches some more satisfactory level -- say, 100 ppm -- you might want to remove a bit of the coral from the filter bag, unless the KH creep has leveled off. If KH stabilizes before getting to 100 ppm after a couple weeks, add another tablespoon to the bag.

This method produces a very slow increase in KH that will have minimal impact on pH. Even if your KH drops when you do partial water changes, it will creep back up before the effects of bioacidification can drive down pH.

Good luck,
Jim

What is wrong with chemicals? That is the easiest way to do it. I use Seachem Cichlid buffer. It buffers the ph to 7.0. As far as hardness is concerned it should level out as your ph levels out. IME acidic water is usually soft and alkaline water is harder. Good Luck.

Why use chemicals when you can do it naturally.....Crushed coral is a natural, much more permanent solution to the KH/PH problem.
Many of us have found that in matters pertaining to PH, when we've used chemicals of any kind the PH bounced all over the place.
Try about 1/2 tbsp of crushed coral. If your results tell you to add a LITTLE more, add until you achieve the results you're looking for.
Len