They are generally siliconed on with a little elbow grease they will come off however I would not put water in the tank without the rim. It is designed to support the tank when its full of water.
I'm interested in this thread I thought the rim would b for support I know when I get custom tanks they ask and sometimes if I don't it has to b thicker glass
I agree with the others here- the rims are for support on rimmed tanks. Rimless tanks are more expensive because of the glass thickness, better design, better epoxy, etc.
Really depends on the size of tank and type. You can remove the rim on JBJ's and BioCubes.
A blow drier will heat and loosen the silicone and then you carefully pry it off and clean up with a razor blade. There is always a risk, but it's been done successfully by a lot of hobbyist.
If this is not a AIO nano type tank I would not remove the rim personally, but others do on 20 and 40 gallon breeders.
Yes it does depend on the size of the tank. Most smaller tanks dont have a brace running across the tank. If it dont have a brace in the middle or 2 braces for 6 footers then you can remove the rim with no worries. Should have asked the tank size in the beginning.
Hair dryer, flathead screw driver and some time. Then razor blade the silicone off. But be ready to deal with unpolished edges that will be a little on the Sharpe side. If you're worried about structural integrity just add a couple pieces of glass strips to the edge and silicone them in place. Kind of like a euro brace.
I removed black trim on 2 tanks..100g visio and 60 cube..not at all for structural integrity..it's there because the edges are sharp and did not order a trim less tank to get poslished..it is easy to do and it's 4 separate pieces. And it has held water for years. Good luck and be careful.