Yes I use RO/DI. This crap has been haunting me for about a year. Ive been doing weekly 25 gal water changes for the past month. I added Rowaphos, carbon, cut feedings down to every other day and I just built a sump thats going to hold an ASM G2 skimmer. In the past month Ive noticed it slowing down a bit. The 4 Mexican Turbos I have are actually putting a dent in it and its not coming back as fast but still kinda coming back. As for the last week or two all water parameters are very good. How long would anyone guess this stuff will take to die off and not return provided I keep my water good? Tank is 90gal with:
100lbs LR(adding another 40lbs)
Mag7 return
4-MJ 900s
Amiracle Wet/Dry w/ bio-balls and built in skimmer(slowly being removed)
Temp-80f
calcium-380
alk-9.3dKH
Ph-8.0day/7.7night
amon-0
trite-0
trate-0 to 0.2 has been at this for about a week
phos-0 has been at o for 2 weeks