# Alkalinity (KH) : ppm <-> dKH



## trc_pdx (Mar 22, 2004)

My tap water (Portland, OR) tests out at zero on my AP KH/GH test kit.

My most recent water bureau report indicates an Alkalinity value of 8.3 ppm, expressed at CaCO3. Am I right in figuring that this is about 0.5 dH, or pretty much no buffering capacity?

The analysis also reports "hardness" (as CaCO3) at 8.6 ppm. Again, about 0.5 degrees?

1) Is SeaChem's Equilibrium a good choice for raising GH to the desired level?

2) Also, is there any reason to add anything but baking soda to raise KH?

3) Lastly, what's the prevailing school of thought on the most appropriate GH for planted aquaria?

Thanks!


----------



## Laith (Sep 4, 2004)

Your conversions from ppm to degrees are correct.

1. Yes, Seachem Equilibrium is excellent for raising GH (and it doesn't raise KH either). Another option is a mixture of CaCl2 and MgSO4 which I've also used.

2. No, baking soda (Sodium bicarbonate) is all you need.

3. I would say you need at least a GH of 5 to ensure no deficiency in Ca or Mg. Be careful however: some waters have most of their GH made up of Ca so even with a higher GH there may be a lack of Mg. But this won't be your problem as you will be making your own GH!

As to upper limits of GH for plants I can only share my experience. I used to religiously use tap cut with RO to keep the hardness down (my tap water has a GH of 18 and a KH of 15). Then I decided to try without RO and use straight tap and I haven't noticed any difference in plant health or growth since: plants still growing too much!


----------



## Raul-7 (Feb 4, 2004)

trc_pdx said:


> 1) Is SeaChem's Equilibrium a good choice for raising GH to the desired level?
> 
> Thanks!


Equilbrium is not only great at raising gH, but it also supplies a good amount of K and Fe with each dose.


----------

