Have you tested your ro/di water for phosphates? Do not assume it is pure. Old filters will not clean the water.
For example: I KNOW my resin in my ro/di needs replacing but I just have not taken the time to order new filters. My output of my ro/di is yeilding a po4 level of around 0.1 ppm. To compensate for this, I simply keep a bag of phosban in my brute mixing container to abosorb the po4 (I always mix my newly made saltwater atleast a day) It works wonderfully! No detectable phosphates This of course is only a temporary remedy and I will order filters soon.
For example: I KNOW my resin in my ro/di needs replacing but I just have not taken the time to order new filters. My output of my ro/di is yeilding a po4 level of around 0.1 ppm. To compensate for this, I simply keep a bag of phosban in my brute mixing container to abosorb the po4 (I always mix my newly made saltwater atleast a day) It works wonderfully! No detectable phosphates This of course is only a temporary remedy and I will order filters soon.