Is the vineager test putting it on the material, and seeing if it bubbles? I did that to a piece I wasn't using. Nothing. I tried white vineager and red, just to be sure I was doing it right. I switched to plexi-glass, but lefts a piece in a smaller tank to see what would happen. Fish became more lethargic, and stopped eating. May not have been slate related, but I took it out, and all is well. I am now dealing with ph concerns. I just can't grasp the whole kh/gh/ph thing. I'm afraid of buffers, so I just mixed 1/4 tap with 3/4 RO. Everything has worked for months (except the 1 day slate scare). Always, my parameters are ammonia, nitrites:0. Ph : really, I don't know. It always seems lighter than high-range lightest (7.4) color, but bluer than the highest (7.6) regular ph test. Is there some calculation, if you know your kh and gh, to find out exact ph? I know stable is best and fish will adapt. But, I showed .25 ammonia for the first time in EVER, and when I tested....my kh was 2. I use the chemical api master test kit. I know under 3 is dangerous for crashes....but my gh was still 6-7. I paced the floors, but did nothing. Later, I retested. Kh was all that changed....to 4. Why does it fluctuate? I have every buffer on the market, I'm just too afraid to use them. And the one time I said "forget it" and started doing water changes with just tap water, my ph shot from 7.2 to 8.2 in an hour, killed a bunch of fish, etc. this was a different tank, thank god, but I can't just "forget trying to change ph". I am where I am, and need help fixing it. If anyone knows of a chart, or can help, please do. Message or post. Thx. My current kh fluctuates from 2-4. My gh has gone from 8-6 over about a week, because of driftwood. I did a water change yesterday for the ammonia, and upped the tap water in my mix ratio..,hoping to up the kh. It seems lowest at night, but I had no plants to be making that happen. Today, I test .25 ammonia, and the nitrite test wasn't to the .25 color, but it wasn't the light blue it always is. Sounds like a mini-cycle to me! I use purigen and nitra-zorb. No carbon. I now have a blue ram flicking and pale. I'm really frustrated! I have 2 egg-filled female angels in this tank, which will devestate me to lose.