Forget Stresszyme, you're only going to add to the problem by adding DEAD bacteria. Get Bio-Spira instead. The only prodoct with live bacteria. Add it directly to your filter, after another large WC.
The latest ph test kit is made by sera.What test kit did you use?
our tapwater is normally 7.5Terror, that is pretty low. Is your tapwater's pH 4.5 as well? Maybe you should test your tapwater's pH and hardness levels.
That could explain why your pH was very low.but our water is quite soft here.
This seems to be pH crash. The hardness levels must be adjusted indeed. Sorry about your situation.last time thi shappened. i lost 2 datnoids. luckily my super red aro was able to take the low ph. it had cloudy eye.