well the "electronic parts" bit relates to anything with magnetic memory, such as cassette tapes, floppy disks or computer hard drives so thats not an issue. however they do typically have pretty potent magnet but I don't think it would be powerful enough to interfere with the electro magnet that the PH
uses to drive the impeller. It deffinitely won't damage anything but may interfere... so try just leaving the cleaner next to the PH
and see if you notice any change in the PH
As far as the PH
's falling down... I don't use the suction cups anymore, I use the plastic over the tank clips for all my PHs now.