# Tricks to keep suction cups sticky?



## crazy72 (Apr 22, 2010)

I can't count the number of suction cups I have, including big ones (eheim heaters) that don't stick anymore. I've tried to remove them and wash them in warm water, scrub them as well as the portion of glass that they go on, but nothing seems to really work well. Any special tricks out there?

I know of the ones with magnets on the outside, by the way, like this one here: https://www.jlaquatics.com/zoomed-mag-clip-magnetic-suction-cup.html. Those work great but they are kind of pricey.


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## TomC (Apr 21, 2010)

The magnetic ones are way overpriced. I have used an old set of magnetic algae scrapers as sort-of suction cups.


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## hp10BII (Apr 23, 2010)

I've heard of people heating their suctions cups with boiling water. That never worked for me.

Method refined (I never tried this so i don't know how well it works):


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## kivyee (Oct 15, 2016)

I would just make my own from this
https://www.amazon.ca/Industrial-Scientific-Supplies-Rare-Earth-Magnets/b?ie=UTF8&node=11850570011

You could encapsulate the magnet in silicone if you are worried about it leaching metals into the aquarium.

or a pre-made alternative

https://www.kjmagnetics.com/products.asp?cat=164


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## Daryl (Jun 1, 2010)

Magnets are definitely the way to go. I have never had any long term success with suction cups.


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## onefishtwofish (Apr 21, 2010)

a bit of vaseline on the inside rim will enhance the suppleness


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## mvanham (Nov 27, 2016)

I went to Lee Valley Tools - picked up some rare earth magnets and metallic cups that enhance the directional force. One cup and magnet on the outside of the tank, one fastened with silicone to the hose/heater/cable holder inside the tank. They work like a charm...

FYI - I did try using them without the cups - the metal-like coating on the magnets themselves is thin and can scrape off if you are frequently moving them. The cups give you something to pry against - preventing the loss of that "coating". Its not a problem on the outside of the tank, but on the inside of the tank scratches in the "coating" - over time, if you are dosing iron in a planted tank - you will get precipitate. I use the magnets and cups on all my 210 gallon tanks now. 

I also double checked my pH calibration - if the pH probe line is close to any strong magnetic field you can bias the calibration. I had no problems and the probes read true.

Mike


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## Gardener (Feb 13, 2011)

interesting. can you post a link to the Lee Valley magnets you purchased?


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## TomC (Apr 21, 2010)

Does anyone have a 3-D printer? It would be an interesting project to buy strong magnets from ebay or wherever and print a thin, plastic two piece shell that could be put over the magnet and sealed with epoxy to make it non toxic. The magnet on the outside of the glass wouldn't need a shell.


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