Ok, well now that my aquarium has recycled, and i have nitrates, i have done two 25-40% water changes this week. My ammonia dropped from 3ppm down to .25, so one more water change should clear ammonia. However, no matter what I have done the last few months (as some of you know), my ph wont budge from 6, except for right after a water change where it will move up to 6.8, then bounce back within a day to 6 again. I have completely cleaned the entire tank many times, meaning done a very thorough gravel vac, and aerate more than enough. As my pic shows I have a fairly large driftwood piece in my 20 gallon. I thought maybe something was decaying in there, but I have reached almost every spot of my tank and moved all the gravel. My only two explanations left are:

1. my ugf doesnt completelty cover the base area of my tank, there is about an inch on one side and an inch in the front where gravel goes all the way to the floor. Slight chance something in this crack, and must be small, has decayed (but what?)? However, wouldnt this affect my ammonia levels (which are usually at zero).

2. that my tap water, which i have tested around 7.6 ph, isnt being tested correctly. Do i need to let it sit out for a day and then test it? if so, what could make tap water turn so acidic by itself overnight?

Any thoughts? by the way my concern is not a steady low ph, but the shock that comes with every water change for the fishies as the ph jumps up for a day.

You can't test your water directly out of the tap. Like you guessed, you have to let it sit over night. The ending pH is a result of the buffering capacity of your water (which relates to how soft or hard it is). The peice of driftwood is not helping your cause either. So, put some water in a cup, leave it out 24 hours, and then test it. I bet it drops quite a bit. I am then willing to guess the rest of the drop is from the driftwood. I doubt it has anything to do with the debris in your aquarium. Let me know the results of your test. It would also be helpful to know how hard or soft your water is. Do you have these test kits? If so then test that as well.

I will do as you suggested and post results tomorrow... i do not have test kits for water hardness, just the API test kit which includes ph, high range ph, amm, ni, na.

I don't think it is neccessary, but why not. Shouldn't hurt anything that I am aware of. The main thing is that you want the water exposed to the air.

sponge bob what time do you check your ph? do you check it the same time every day? also i found this site. lots of other info 2
http://fish.mongabay.com/chemistry.htm

I really don't worry about what's under the plate. My tank stays at a pH of 7.0 because when it starts to go down I do a water change and get it right. It will be about the samre the next day as it is when I first add alkaline water from my tap. So far along with my Phoscheck in my filter and keeping the pH at 7.0 the brush algae doesn't seem to be growing back. The sopts where I didn't remove the algae it seems to be a little ragidy, as if it isn't growing, but it still seems alive. The Java mosss is growing over it and taking over, so I think things are under control with this algae. I've been diluting and removing the copper as it didn't seem to do anything.