Ph Confusion

[Proxo]

Currently set up a plastic box as a quarantine tank, i used the water from my tank to make it a little easier.
However here's what i don't understand, the pH in the Q tank is 7.6 and the pH in the main tank is 6.8.

There's roughly the same amount of wood in both too as this can drop pH, i think.
Why would the pH in the Q tank go up so much?

Treatment is melafix, just incase that has anything to do with it.

 

[Aqua Tom]

Leave it 24 hours & test again. i imagine your tapwater you added to the main tank when you used its water for the Q tank is a lower Ph. It will probably rise as the suspended CO2 off gasses.

 

[Proxo]

I used all water from my main tank into the Q tank and then refilled the main tank with tap water.
It's been set up for 3 days now.

Main tank pH: 6.8
Q tank pH: 7.6