[uhuru]

Austin, HCl will do the job, vinegar will not. Depending on how thick it is it comes off a thin layer at a time. So repeatedly spraying, letting it soak, then wiping with a damp towel actually worked better than scrubbing...also prevents scratching up the overflow which you don't see until it fills with water and the light shines on it. So just let the chemicals do the work for you. Also place towels all along the bottom to absorb the hcl as it drips down.

I have no idea what to do now that there is water in the tank other than religiously scrubbing the overflow even before I see any coralline. I think one thing elks should have done on the new model is make the overflow smooth.