my rocks are actually lowering PH
I posted elsewhere but it seems the forum has lost it/ not posted successfully
These rocks which I found in New York City Central Park by breaking open a boulder of Manhattan Schist ( Schist high in black mica, iron, and low in heavy metals) are actually lowering my PH by about .3-.5 in a few days. I tested these results by putting them in a quart of water by themselves and testing and the results were exactly the same, they brought my PH from tap6.9-6.6 or so. Everything says this is impossible, unless the incredibly polluted last 200 years of NYC history have somehow imbued a pollutant or many into these rocks. They are admittedly much more porous and friable than they were supposed to be with all the mica. Am I a complete fool to have put these in my aquarium? The LFS sells rocks at truly exorbitant rates as you might expect in Manhattan and I am poor. I figured they would be fine since they are a hard stone and typically inert. I got them from a relatively unpolluted part of the city though the air is still polluted. The thing I think of is some sort of acid rain type of compound in the rock from years of sitting on the ground in NYC. any thoughts? If the PH is 6.5 that is not the end of the world. Was eventually planning on adding a pea puffer
Any ideas on what I might keep? I really don't want to use water additives to tamper with chemistry and am pretty bummed out this happened. Also, I can not get my ambulia to root.