RO booster pump advice

[P4dstar]

Yeah, 4040. My output is diabolical when my TDS is high. When it's something like 450ppm, which it basically was all summer, it was coming out of my RO at around 70ppm. Think I worked out my RO is only operating at around 85% efficiency with my PSI being so low. I knew I needed to do something so instead of going the pump option (for now) I ordered another DI vessel to help with the resin. I'm still contemplating another pump though. Current set up is Tap > pre filters > RO > DI > DI > tank.

I have just found another connection I needed for a spare DI I have, Touch wood I won't need it for a while with an output of 6 though haha. Either way i'll add it in the next time the resin is spent.

A pump is the only difference maker I can think of but 70PPM is painful mate. The highest I went to was about 33/34.... I feel lucky now!