Thanks everyone
. As for the rock, one of the blessings about the Minnesota river valley is the massive amounts of FREE rock you can fine on the side of the road. The MN DNR calls this shale. It is a layered sedimentary rock which has a darker gray color. Unlike the traditional limestone which is yellow (ugly yellow if you ask me). The rock that is in the tank it was washed, baked and shaped, which was the fun part (hammer and chisel)
. I was unsure of what it would do to my already high
pH (8.2) but after a week of testing in an empty tank no changes in the water chemistry. The best part about it all is FREE!!!!!!!!!!!!!! and I still have approx 100lbs in my garage for later use or sale for if anyone in the area that doesn't want to deal the the cleaning and shaping work.
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