Two options to consider? If it is a small tank as you mentioned moving it , perhaps tilting it up a 1/4 to 1/2 inch would let you spray something like vinegar in under the edge and then use both hands to slide a towel in the wape around to clear slow any mold or fungus that is starting. Important to wipe down any collected spray, though. Perhaps while tilted slightly, leave it tilted and place a fan or hairdryer if one that stays cool is handy.
One reason for not using a pad of any sort under my tanks is that most of us do spill water and it does get under the tank and can lead to various problems with the top. My wife tells me my nose is dead!!