Just replaced all filters, membrane, and resin. TDS in: 381 TDS out: 2.
Been running a little over ten minutes. Do I need to run longer or is something wrong?
Your membrane is what rejection rate? If spectrapur or BRS it's 99% so 1% of 381 is 3.8, nothing to complain about. It's actually working better than it should. If that's out of the resin then something is wrong with the resin. If your TDS going into the resin is 381 then the membrane is broken. If TDS going into unit is 381 and out of membrane but no DI resin is 2 then it's fine.
Can you check the TDS going into the resin? Something sounds very bad with the membrane. The TDS coming out of the membrane should be 3.8 as I stated earlier. A full container of fresh resin should have no problem removing the last bit of TDS. Unless the membrane is not removing 99%. The higher the TDS into the resin the more contact time it would need to remove it all. This makes me think that either your membrane is bad or the resin is bad.
Brand new membrane, filters. The resin is old but was in a sealed bag. I have no way at the moment to check before and after membrane. My Tds meter is hooked on the bad water in and on the good water out.