on day 19 of the fishless cycle, ph was up at 8.1, was reading on internet that some ph down was actually a good thing for the bacteria growth, and that the nitrite to nitrate bacteria do better at a lower ph (around 7.6) so added some ph down, i think it was a big mistake. Im now on day 30 and my ammonia has been at 0 everyday since today, its at 1.5 ppm? my nitrites have gone up then down, then back up and now are at 0? nitrates have done this as well. I decided to do a full workup and found that my ph is at or below 6.0! i tested the ph after adding ph down and read it at 7.6, tap water is 7.6. I did add a large piece of mopani about 2 weeks ago, but not sure if it would have lowered it that much. Should i just add some ph plus or do a parial water change to try to get my levels back to normal or let it run its course?? ( shoulda done this in the first place...... )

Your mopani is probably acting as a buffer but it would be hard to tell since you used chemicals, which btw I'd never recommend because buffers are so much better. They change ph slowly, they hold it steady, and if they lose their buffering capability over time, your ph will also very gradually change over time. Chemicals just suck...and since you used the ph down it'll be hard to tell whether or not the wood buffered your ph at all. If it turns out the wood isn't enough try filtering through peat if your filter has enough media slots. I've never tried it but understand its a very effective buffer.

Try to get things back to normal by doing water changes. Chemicals such as ph up and down just leave too much room for error and mistake.

I'm learning so much that helps here. I bought some PH Neutral since we have a high ph out of our tap... 8.4 measured on the weekend. Well, I found that that stuff didn't do anything for my tank when I used it a couple months ago. Once I really started reading more, go with the natural remedies... ie: driftwood and rock. If only I would have known, I wouldn't have taken that piece of driftwood that I bought originally back...