Hi y'all! Thanks for all your terrific input! I really appreciate it
Well,i decided to take the more "wait and see" route and keep testing my water. I still do a 1/3 water change every week,like I do with my other tanks. No probs with them!! But, this one tank is still doing it's silly pH thang! I just decided to do the leave'er be and just keep livebearers (platys) in it...took the poor little corys out and put them into another tank.
I took everything out of this weird 20L,tested every item...no fizzing
,and added each item back into tank one at a time...testing the water each time...nothing! Until everything was back in place!!! Back to 7.6 again!! I gotta laugh here...the only thing that I didn't check outright was the tank itself,ya know,with the water out of it! But,I'm done...just gonna have livebearers in it!!
Now,kinda new question...are there ANY bottom feeders that do well in a 7.6pH tank???