oh ya, no worries. I've done exactly what he's done, 2 days later the tank was full of brown snot again. I left it in complete darkness for 4 days, then actinics only for 2, then re-acclimate the tank to MH for a week. 3 days later, tank full of brown snot.
Finally got it to disappear, posted pics of how good my tank was doing, 2 weeks later, tank full of brown snot.
Tank is now just clearing up again, but hopefully it's decommisioned before the next wave of brown snot...