heater suction cups are insufficient, ideas?

^&right · Mar 7, 2026

Problem solved. With water in the tank they stay in place. Thanks for the responses.

^&right · Mar 7, 2026

deleted

Ryan - Serious Reefs · Mar 7, 2026

A dab of silicone on the back of the cup. One below can be found at most Home Depot in the paint area next to the super glue. The package clearly states aquarium safe.

Use a tiny dab so it is just a thin film that will cure underwater. Good news is while it will hold the cups in place you can still peal them off if the need ever arrises.

https://www.homedepot.com/p/Loctite...ve-Sealant-2-7-oz-Clear-Tube-908570/303769575

PolypPrism · Sep 12, 2026

Ryan - Serious Reefs said:
A dab of silicone on the back of the cup. One below can be found at most Home Depot in the paint area next to the super glue. The package clearly states aquarium safe.

Use a tiny dab so it is just a thin film that will cure underwater. Good news is while it will hold the cups in place you can still peal them off if the need ever arrises.

https://www.homedepot.com/p/Loctite...ve-Sealant-2-7-oz-Clear-Tube-908570/303769575

Can this be done while running a reef tank? I was thinking about the gas off?

Ryan - Serious Reefs · Sep 14, 2026

PolypPrism said:
Can this be done while running a reef tank? I was thinking about the gas off?

Have I done it? Yes. I’ve used a very small amount in situations like this and haven’t noticed any issues. I always add fresh carbon when I roll the dice with something like this.

That said, I’d still consider it a higher-risk move because of the unknowns. The common concern is that it can off-gas chemicals as it cures, and standard silicone generally cures slow underwater.

Strong magnets are the safer solution. The modular AvidAqua magnets are what I use when they make sense. I like that you can shake/rattle them to know they are not leaking.