An overnight soaking will NOT harm your filter(s). The filter cleaners formula is designed for a "get em in and get em out" type cleaning. We endeavored to make the product powerful enough to work quickly as most people are busy with other things most of the time. So, soak them as long as you like, hose them off and let them drip dry. I really like to see cartridge filters inserted into the filter well when dry and not wet. An older very talented service tech told me over 25 or 30 years ago that you should always insert dry filters into operation for longer life cycles.
ideally, you have a spare filter set that you can use while the just cleaned ones are drying. One other thing! Our cleaner gets them very clean but they will not look white as they do when new. If you want to whiten them up just spray a little bleach on the cleaned and dry filters and the white like new reappears. For the TFP readers who have pools with Sand Filters, this cleaner will get so much gunk out of your sand bed when used correctly. It is a little tricky as to how this procedure is done so read the instructions on
www.Ahhsome.com. Another thing, even though your water tests fine and the water looks great remember that the filter(s) can harbor some very nasty particulates and they build from deep inside the pleats. Even a good garden hose rinsing misses a lot of the contaminants.