[KCV6]

I always run the tank up to temperature with air agitation on then filter once it is up to temp. I also always check the PH with the tank heated and air agitation on.

Also if you charcoal filter, re-run the tank up to operating temperature with air agitation on, then add a full re-charge of brightener before testing PH. Leave the tank to run for a while before checking the PH. When you check the PH it will probably be high, so using a small syringe or eyedropper, add a few drops of acid as required to bring the PH back down to the recomended operating window.

Cheers

Mark