So I bought a tank back in January, it came with an RODI unit. In March I decided to replace all the filters and the membrane. If I recall correctly even after replacing the filters and membrane the TDS was like 2-3 which it shouldn't have been but a friend of mine bought a brand new unit and brought some of his water over and it tested the same so I just went about my way. Fast forward to today, I am having what I believe is either cyano or diatom issue. So I am going through to figure out what is causing it. I test my water and its coming out between 11-16 so I think everytime I top off or do water change, I am adding bad water into the tank. I can't figure out the issue with the rodi and why it wont go to zero tds. Incoming water is like 158 and coming out of the membrane at like 11. Then it goes into the di and comes out still 11. I just went and bought new DI repacked it as tight as I possibly could and it changed nothing. I also tested my tds meter at the lfs and it worked fine so I don't know what else to do. Any ideas? I'm ready to throw the whole thing out my window and buy a brand new one. Thank you!