QT PH crash
I have experienced something odd when i tried to quarantine a few fish that i am wondering if i should even do it.
Starters... here are my water perimeters.
Ph 8.0ish... after a few hours it settles at 7.6
Ph 6.0 (ADA AS is buffering my tap)
GH 6 (need to dose GH booster for my plants)
To begin i have a 72 gallon with maybe 20 fish all seem healthy and have no problems. I wish to add a few more fish and i went to LFS where the tanks seem decent and when i purchased 4 fish (rainbows)all from the same tank they all ended up dieing after a week (placed in my 72).
I decided im no longer risking my healthy fish and will use a quarantine tank from now on since i have old filters, heater, and a 10 gallon tank laying around (never done a QT before) I go to a different store in another city and buy the same fish. This time i place then in the QT tank after i acclimate them for about an hour... every 10 mins placing a bit of tank water into the fish bag. Now im not sure if this was a mistake but i used water from my 72 to fill the QT because i figure i want the fish to be use to the lower PH, KH, and GH.
All is fine for 24 hours i come home from work and test the QT water and notice the PH is 8.6. Wow what happened? I changed about 40% of the water because this seemed extremely odd and one rainbow have a bit of red on his side. I tested the water a few hours later it was 6.6 and it has been stable for 16 hours now... but the rainbow with the red side didn’t make it.
My question is what happened? Why did the PH crash? And is it worth it to QT if this is going to happen.? I called the fish store and they informed me their tank has a PH of 6.8 and KH of 1-2. They dont test the GH on fresh water tanks.