RO/DI problem

[Jr'sReef]

Need some help trying to figure out what's going on with my RO/DI unit.

It's a 4 stage from brs with a 150gpd water saver unit. Incoming tds is around 150-180 but my outgoing or product is reading 15-20tds. I replaced the sediment filter, the carbon block and di resin with no change. Unit is about 6 months old maybe ran about 600gallons on the old resin and since the new resin and water saver upgrade maybe 150gallons of RO made. Can't figure out why my tds is staying at 15-20

I checked the membranes and both are seated correctly.

All tubing seems to be installed correctly as of BRS instructions. Also have a flush kit which doesn't seem to make a difference.

Any help or suggestions?

 

[chipmunkofdoom2]

After DI resin you should be getting 0 ppm TDS, almost regardless of how well the rest of your system is functioning. If you're using new resin, I suspect it might not be packed tightly enough and the water may be bypassing the resin without getting proper contact time. Did you follow BRS's instructions and make sure the resin was packed tightly?

It's also worth noting that if the prefilters hadn't been replaced in a while, it's possible the carbon block was exhausted, especially since you only have one. An exhausted carbon block will let chlorine/chloramines through, which will damage RO membranes in fairly short order. You should check your RO membranes to make sure they're still working properly. Check the TDS after the membranes, but before the DI resin. The TDS should be 4% or lower of your tap water's TDS. Multiply your tap water's TDS by 0.04. The water coming from your RO membranes should be equal to or lower than this number.

 

[Jr'sReef]

Thanks, going to check that