Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
KH controls the pH.
With a KH of 7 German degrees of hardness it will be difficult to control the pH. Anything you add to drop the pH will not work for long, and the carbonates will make the pH rise again.
GH is too high for specialty fish that need soft water, and at the upper end of most community fish.
Get some reverse osmosis water (a gallon is fine, grocery store or fish store) or distilled water.
Make a few blends of tap + RO. Make a cup or two of each recipe. Try:
25% tap + 75% RO
75% tap + 25% RO
Test GH, KH and pH in these blends. See which comes closest to the ideal paramters for your fish. (go by the GH).
Then add a handful of Peat Moss.
Stir, and let it sit overnight.
Test GH, KH and pH.
If this does what you want, then you will have to go into the water production end of aquarium keeping.
To set up the tank, make enough of the recipe to fill the tank, and a little more (to prime the filter).
When you are thinking about doing a water change you will need to prepare the water ahead of time. I would do this in a Rubbermaid Brute garbage can on wheels, and roll it into each room with tanks that needed that kind of water. I used a knee-hi stocking full of peat moss for the black water fish. I got several uses out of this much, though it would take a bit longer as the peat moss aged.
Top off evaporation with RO water.
Select fish that thrive in your water.
Last edited by Diana; 07-24-2015 at 01:26 AM.