You shouldn't have to cover your tank from all light if it's just a bacteria bloom (somebody correct me if I'm wrong), that's just with algea blooms...
The only time I've had a bacteria bloom, I simply did 10-15% water changes (including gravel vac) day-after-day until it went away. It took all of 3 or 4 days of back-to-back water changes and my water was clear once again.
I did another small water change 2 days after that just for safe measure.
You'll notice it gradually get better and better after each water change until it's completely gone, but that should be all you need to do.
did a couple of water changes and it is fine now. i hate when this happens. i do regular water changes and am anal about my water parameters. i dont understand why this happens. this is only the second time it has happend to me but it still pisses me off
If its a bacteria bloom is it possible that you are overfeeding when it occurs. Does this happen after you clean your filters ? It's weird, usually you shouldn't have any bacteria blooms in a cycled tank unless something happened to your bio filter. Maybe you had some power outages ??
-- Edit -- Next time it happens test your water before any water changes for ammonia, nitrite, nitrate, and ph. Water tests tell alot in these situations.