I forgot I actually had a floating hydrometer a long time ago. It wasn't made by tropic marin though. The only thing I remember about it was that it was very hard to get a reading from it. The spaces between the incraments (sp.) of measurement were so close together, and the way the water level sat around the thing made it very had to distinguish an exact reading. Then there's the fact that I had to turn off all pumps in the tank to use it.

How much do the tropic marin hydrometers run? If they don't cost too much I may look into one. Kind of like a Dr.'s second opinion.