Boo said:
More water movement in the affected area will help as well. That stuff likes to start up in areas of low current.
Might shift the powerhead toward the front a bit then, stir it up. Thanks for the advice.
-EDIT-
Hahaha I'm so crap at this I even kill non-living things. My hydrometer was getting impossible to read due to algae, so I figured I'd do what I'd heard of people doing and put it through a light boil with a shot of algaecide in a pot of tank water. Already done it once with no issues. This time it warped. Yep. It changed shape, and the needle couldn't move past this new bulge in the plastic.
At least I did this AFTER making a new lot of saltwater for the next few changes. Oh well, guess I'll grab a new one tomorrow.
Also, the digital thermometer was a much-needed addition. My tank seems to like roughly 28.5° Celcius. I'm expecting that to drop overnight of course, and I have my heater set as close to 25°C as I can get it (it goes from 24° to 26°).
Mr Cowrie snail was sadly a casualty - I uncovered his empty shell while siphoning some of the crap off the sand. Shame too, I really liked that guy. R.I.P. Mr Cowrie, enjoy the giant aquarium in the sky.