I am interested in your expanded shale experiment. After reading online that it was inert and then seeing that mine was not just made me think maybe it was just shipped in a truck or stored in a place that once had limestone or something with higher PH. I figured over time it would neutralize with my acid additions.


The plants would like PH of 6 but I figure going that low would be more harm to the fish than help to the plants.

I get some signs of what i think is iron deficiency at 7.2+ on some plants, catnip leaves turn yellowish first. But it gets green within a day of lowering my ph to 6.8-7. Which is why i found that PH range to be my desirable sweet spot.

It also may be worth mentioning that I dont have to add acid to keep my PH if it rains enough to keep my water level up. (dallas)

Even with this new information, I think i will continue to use expanded shale because all things considered cost, weight and porous-ness outweigh the negatives for me.

brian