I have been running a 28 Gallon Nano for a few years now. No issues.
After I moved to Poway, started getting green algae. Did the normal checks.
Then decided to check my RODI unit. 77 PPM coming out of the unit. Ouch.
So replaced the sediment filter, carbon. Upgraded from a 75 GPD membrane to a 150 GPD with the correct flow restrictor. And changed out my DI resin.
Flushed everything out. PPM out of my membrane is still high. 500 PPM tap. 55 RO, 3 ppm after DI.
I was hoping 40 ppm or less. Any ideas?