My problem has always been getting the pH to go down, not up.

Dwayne

wrote in message
...
I do a lot of hobby hydroponic growing. I have noticed acidity building up
in some of my pots. I attribute it to the preferential consuming of
potassium that leaves the nutrient solution more acid.

Today, I bought some marble chips. I placed a handful in several of my
nutrient containers. My expectation is that as the solution becomes more
acid, the marble will decompose giving of carbon dioxide and thereby
consuming some of the acid. I will report on whether this keeps the pH
above
6.0.

Has anyone had experience with this kind of pH control?

Bill