Magnets for sponge filters

[GaryE24 139]

I have some suction on to the glass sponge filters I quite like for small tanks (5 to 20 gallon). But suction cups are limited, and they'll fail. I'm wondering if I could crazy glue ceramic magnets to them, with a magnet on each side of the glass to hold them in place. I have a powerhead that uses a system like this, and it's excellent.

I'm looking at magnets about the size of the usual aquarium suction cup. But before I'd do this, I'd like to tap into the experience of people here. Has anyone here used such a system or gained any experience that would help me decide?

 

[Magnum Man25 139]

I would think so… I am looking at this wave maker… I hate suction cups, but found this one that uses magnets, I’m thinking about trying…

https://www.amazon.com/gp/aw/d/B0C1NLDFWD/?tag=fishforums-20

if they’ll hold a wave maker, they will certainly work on a sponge filter…

 

[Tomsfish4 47]

My Jeboa crossflow is attached with magnets and has never fallen off or even moved slightly.
I have been running the crossflows for many years now.
Had them in saltwater also without issue.
It has been a long time since I had suction cups in any of my tanks.
Last ones were on thermometers and always came loose causing to me have to search for the therm.
I eventually started removing the suction cup and just let the thermometers float randomly.

 

[Magnum Man25 139]

the only suction cups still in my tanks are on the heaters, and none of the heaters is actually stuck to the glass anymore…

 

[GaryE24 139]

I'll try the magnets then - a small pack to start and see. I have a powerful water pump that uses magnets, and a few no longer used algae scrapers.

 

[Uberhoust3 2]

I think magnets would be great, but I think I would use pretty hefty magnets so that you can encase them in epoxy or some other sealant first. Not entirely sure about the toxicity of some of the rare earth magnets they make today, not all will be suitable for immersion.

 

[TwoTankAmin19]

I used to think magnets were a good idea. I got a few heaters that used magnets and then discovered the downside. The other half of the magnet set-up is on the outside of the tank. When working in the tank or around it ans bumped the outside magnet it came off the glass and the heater detached went to the bottom of the tank. I also managed to knock of the outside magnet without realizing it. But a thermometer on the bottom of a tank is not a disaster.

However, a filters or a powerhead falling down would be. Yes, suction cups can let go. So either way one has a risk. At lea with powerheads there is an attachment which slides onto the powerhead and it has 3 suction cups. This works better than a singl suction cup. Also many of them have an adapter that lets one hang them on the top of the tank. However, this means the equipment must be hung fairly high up in a tank.

Like any of the equipment we use there are better and worse suction cups in use on the various equipment we might buy which uses them. I have some scution cups which are difficult to detach. The little grips are hard to grab and I often have to use my algae scraper with a SS blade to pry them off the glass.

 

[Tomsfish4 47]

I think magnets would be great, but I think I would use pretty hefty magnets so that you can encase them in epoxy or some other sealant first. Not entirely sure about the toxicity of some of the rare earth magnets they make today, not all will be suitable for immersion.

Aren't pump impellers magnets?
They are in constant contact with water un protected.

I know for algae scrapers the magnets are protected but I think that is just how they build them and not necessary to keep the tank safe?

 

[Uberhoust3 2]

Aren't pump impellers magnets?
They are in constant contact with water un protected.

They are, but they are engineered for use in water, and actually not very strong, you would have a hard time getting them to work through glass. Your typical button type rare earth magnet is not the same, they are susceptible to corrosion, see this brief article: https://www.samaterials.com/blog/how-to-prevent-magnets-against-corrosion.html

 

[GaryE24 139]

The one magnetically held pump I have would knock you over before you could knock it off. It is well made with a serious magnet. . For these sponge filters - the design is good but the attachment is weak. The suction cups will fail. But that'll be at the back of tanks where I rarely either work or lurk.