No KH with low ph

[DiscusDuo]

we are fairly new to the discus hobby, and have a question. There is no kh in our tank water and our ph is about 5.0. Our Gh is 11gh. we are using half DI and half aged tap water for our water changes. Aged tap water has a ph of 7.0, Gh 4, KH 0. what would be the best way to bring our KH up to a good level.

[chavez720]

Baking soda is the cheapest - 1 g/10gal will raise kH 1°. Commercial products are also available. The ingredients are usually carbonate salts. Both will raise pH considerably though.

I have also used Seachem Acid Buffer/Alkaline Buffer in combination to achieve a set pH, but not to adjust kH. The alkaline buffer is a mixture of carbonate salts. Could try and add Alkaline buffer to raise kH and add enough Acid buffer to bring pH back down.

1/4 teaspoon of baking soda will raise the kH approximately 1 degree in 13.5 gallons of water, so do the math to get what you want. You probably want at least 3 degrees KH to prevent a pH crash.
brad

[DiscusDuo]

do we need to add it to every wc since our tap has no KH to keep the level stable?

thanks for the info

[chavez720]

For topping off at evaporation no - salts will stay.

WC yes because you are also removing the salts.