Water level too high

[IJC]

I'm looking for a way to lower the water line in my tank without taking everything out. The water is very close to the bottom of the trim (on the inside rim) and I'd like it to be about 2 cms lower.

The only way I've thought might work is using a cutting disc on a grinder. I'd syphon out some water, and maybe use a cardboard box with a hole in the bottom (the size of the overflow box) to catch the cuttings. I think the potential mess is the biggest problem, as well as being able to do a half decent job in a half-full aquarium that's only 18" wide.

The other thing I thought might work is some sort of hot knife. We use these on the fishboats for cutting ropes. I'm not sure how well they would cut 3/8" acrylic however, and it might be a pretty messy job too (would almost definately set my fire alarm off).

If anyone has done anything like this, or has any insights please let me know.

Ian