I was wondering if anyones had success using a dab of silicon on their suction cups? I know magnets are prefered, but I just don't have that options ATM. Would love to hear people's experiences.
I've tried it. Silicone adhesive will not stick to most suction cups long term. It will stick to glass well long term, only coming off with a razor blade.
That's an interesting idea and something I had never considered. I would expect that it could work but that it will depend upon what the cup is made of. Some cup materials probably would fail to adhere to silicone just like it doesn't really adhere (bond) to acrylic. I understand that suction cups can be made from plastics and rubber so I would put a dab of silicone on the back side of the cup, let it dry there and see if it sticks. If it does, and if you have a glass aquarium then I would try it on the front side. Silicone can be removed from glass with a razor blade, but use a small dab to minimize cleanup if you ever want to remove it.
Edit:
Look at that! @fryman said the same thing with much fewer words. He gets an A for being concise.