How much crushed coral?

[snickle]

I use distilled water in the drop checkers.

The low PH I blame on the bog wood in my tanks.

[ingg]

Easy KH buffer from your pantry is baking soda.

Better one for a planted tank is had from beer/wine making supply houses, potassium bicarbonate - this also may be found in gourmet/specialty food stores as a low sodium option for baking soda.

[RTRJR]

We have massive variations in water supply in the metro areas (DC/Balt.). My water is moderately hard and almost equally alkaline. So long as I keep up with partials, I have excellent stability. Some of our NVA folks have very soft water. There are too many different water sources and water processing techniques to generalize around here. My water is different from even that in Frederick, at the bottom of the hill (excuse me, mountain), but the differences are not so great as to shock fish in moving them. Middletown (the other side of Braddock from Frederick) has surface water, so softer, but it was loaded with iron when we lived there (>20 years ago) - lots of sink and toilet tank stains. And that is in a range of less than 5 miles.

KHCO3 is good for alkalinity adjustments for planted tanks - but not directly in the tank please. Mix separately and add slowly if you have to make any non-trivial changes. Osmotic shock can happen.

[Jeff120]

I use distilled water in the drop checkers.

The low PH I blame on the bog wood in my tanks.

I think the problem is the distilled water, it has a KH of 0 right?

From what I have read on the net you want the water in the drop checker to have a KH of 5. I forget why but folks have tested and that seems to be the most accurate for measuring the CO2.

[snickle]

I use a KH solution of 2. It is a mix of distilled and sodium carbonate.

[fredyk]

KH of 4-5 because most ph test solution is the blue stuff whcih becomes green at ph 6.8. or rather in layman's terms, the blue stuff becomes green when the CO2 concentration is good.