I'm done. Tearing it down again. The tank is a white fog with long white stringy bacteria growing 6 to 8 inches in a day.
I feel your pain, man. Going on 5 months here and I have finally made the decision to tear down and start over. The post on the last page about a bad membrane piqued my interest since I made a newbie mistake with my membrane in the beginning. But then I remembered that the stringy bacteria started 5 - 7 days after my cycled finished. I do not carbon dose, I never have. What I have narrowed it down to is 1) Dry rock. All marco rock, nothing live. 2) Silicone. I made the mistake of buying GE II Door and Window for the second half of my build. 3) Dr. Tim's One and Only. I've decided to tear down the the tank and start over with live rock this time, new sand and even bought Aqueon aquarium silicone this time. Planned on tearing out all the questionable silicone that I put in and replace it with the safe stuff, if only to remove a variable and have peace of mind.
What's weird is bacteria goes through an explosive growth spurt after each water change. This makes me question the idea that the problem is within the tank and rather something being introduced.
Some things worth noting about my build, maybe we can find something in common here and try to narrow it down.
40 breeder, 20 long sump. Both bought at $1/gal sale.
All plumbing bought from HD, bulkheads from BRS.
Eggcrate placed at the bottom of my tank, covered with Caribsea Fiji Pink and dry marco rock.
0 TDS DI water with Reef Crystals.
Dr. Tim's One and Only to cycle tank quickly. 18 days later, tank is cycled.
5 - 7 days after cycle completes, rock becomes covered in what looks like stringy spider web.
At some point, I add AlgaeBarn copepods and dose AlgaeBarn phyto two or three times. Stopped dosing phyto after someone on RC said to stop.
I upgrade my SpectraPure 90 GPD stock membrane to a SpectraPure 200 GPD membrane. Made the newb mistake of putting 90 GPD membrane in an opened bag and placed in closet. Didn't know at the time that letting membranes dry out could cause damage. Switch back to 90 GPD after a week or two.
Those are the only events worth mentioning. Since then, i've spent almost 5 months now doing damage control on this tank. I've gone through 4 large bottles of Waste Away with little improvement. Once a week, I get in the tank and spend anywhere from 2 to 4 hours removing all visible slime with a turkey baster and siphon. I take the skimmer cup off, clean it thoroughly, wipe off the inside of the neck and do anywhere from 10 to 30% water change. Using a 4 stage 90 GPD RODI, my water is 1 TDS post membrane and 0 TDS post DI. I mix either in a food grade white HD bucket or a Brute trash can with Reef Crystals. Immediately following a water change, there's usually a 2 - 3 day explosive growth spurt, then it slows down, as if it has burned through whatever food source it just received.
Also worth mentioning: I have 55 gallons worth of water volume, and only 1 fish currently. I feed that one fish a pencil eraser sized amount of frozen mysis shrimp once per day. My tank is also ultra low on nutrients, so much so that my macro completely died. No detectable NO3 or PO4.
That is
3 days worth of skimmate. Skimmer overflows so fast pulling the bacteria out that I had to rig it to drain into a gallon pitcher.
Skimmer every few hours. I have to create paper towel "hammocks" to prevent the skimmate from dripping back into the tank.
Needless to say, I am done. One can only do so much until it's time to jump ship. The bacteria is so plentiful, it will clog a filter sock in 45 minutes, causing it to overflow. One time it clogged a sock, sock fell over and like a pitcher, poured all water onto the carpet. I woke up to a wet floor and a salinity crash due to my ATO dumping freshwater. My Bangaii survived but the only other inhabitants (two hermits) died. Whatever this is, whatever causes it, it is absolutely brutal and it is the quickest way to kill ambition and passion for this hobby. It took a lot of persuasion from friends and family try again from a clean slate rather than jumping ship for good. I just hope I don't run into this again after tearing down, spending hundreds on LR and new sand.