whenever I turn on my rodi to brew up some water, the tds always spikes up from 20ppm sometimes up to 70ppm (depending on the last time I used it). I always let it run until it comes back down to 0 then dump out the “dirty” water and start from there. This isn’t a big deal but my question is.. if I were to use a large drum with a float and just left the rodi on to fill, how can I stop the tds from spiking when it kicks on automatically?
Rodi tds spike
- Thread starter G_Lows
- Start date
- Tagged users None
I have tried that and it still does it. I could try flushing longer, I usually flush for 5 min. It was a brs 4 stage but I added another membrane to make it a 5, 6 stage if you include di. I bought it off my friend like that and he never had that issue. Tds going in is around 180ppm
BeejReef
2500 Club Member
Don't know how to avoid the initial TDS surge in a "set it and forget it" RODI resevoir, aside from manually starting it and discarding first few minutes, as you mentioned. However, you can set a low and high level sensor in your RODI reservoir so your RODI only kicks on when the reservoir needs a fair amount of water. That means you're only getting one TDS surge, and not one ever 38 minutes when you're ATO marginally drains the reservoir and your RODI obligatorily fills it back up 1/8th of an inch.
