Bacterial Bloom


New member
I'm working on my new JBJ 28 build and I received most of the equipment about two weeks ago. The one thing that is holding me up is the RO/DI unit (a plumbing issue that should be taken care of tomorrow). I couldn't stare at all these new goodies for two weeks without putting water in the tank. So I proceeded to add plain old tap water so I could leak test, test the rest of the equipment and play with the ReefKeeper.
Within two days the water was white, and has a film on the top. There is good water movement (2 main returns and an MP10), and aeration (Tunze 9002 skimmer). This is a nano and you can't shine a flashlight through from one side to the other. After reading up a bit, I killed the lights which had been running 8 hrs for the main and 10 for the actinics. For giggles (and because it is hideous to look at) I added carbon and it didn't make a dent.

Here is my question and concern: When I drain the milk from the tank, should I take any steps to clean the tank prior to introducing the fresh RO/DI saltwater? I was planning to rinse it with the RO/DI, fill the tank with plain RO/DI (no salt) to let it run through all the pumps for an hour, drain it again, and then introduce the saltwater. I know this stuff reproduces at crazy rates, so I am not sure if a few leftover bacteria will repopulate the tank.
I haven't ordered rock or sand yet, so once I do get the saltwater in the tank (hopefully this weekend), it may be another week before I begin cycling. Will the bacteria repopulate? Should I hold off on filling the tank until a day or two prior to my sand and rock arriving?
I just want to avoid starting a brand new tank with the deck stacked against me.
I attached a pic "“ it's much worse now than what you see here.
Any advice is appreciated.


New member
Lesson learned, drain all of the water out & start with RO/DI water & you will be fine, the bacterial bloom was feeding off something in your tap water, eliminate that & the problem is solved. Good luck to you.