How important is carbonate hardness (KH)

[knicks791]

The KH reading in my tank is very low, is that bad? All the other readings are good.

 

[Bderick67]

Low KH makes for a very unstable pH, possibly leading to crash

 

[knicks791]

How is it fixed?

 

[kdrun76]

Adding crushed coral in your tank somewhere is the easiest way. Mix some in your gravel or put some in a panty hose sock in your filter.

 

[nfored]

Adding crushed coral in your tank somewhere is the easiest way. Mix some in your gravel or put some in a panty hose sock in your filter.

Amen Brother.

I used to have this problem, until I dropped about 30lbs of ex live rock in my tank. My buddy tore down his reef tank gave me the whole setup, I dried the rock for a few months and tossed it in as decore. Now no matter what my pH is at 7.8.

While I don't have the kH reading I know it must be boosted since my pH was always like 6.0 maybe lower. If I did a 100% wc on a test tank it would drop to 6 in 1 week.

 

[DemonShark]

Its not important unless you're doing a heavily planted or reef tank.
Fish don't seem to care too much, but it couldn't hurt to just add a bit of baking soda when you do your water changes and it'll bring it up. A tablespoon every 10-20 gallons for each water change is plenty and its perfectly safe. Its the easiest and most stable way.