NanoGurl's 75g Reef Thread

[melev]

If you had a Tee in the line after the RO membrane and before the DI resin, you could let it run for 1 minute into a bucket or nearby sink, then take a sample of that water in your stolen McDonald's cup. Test it for TDS.

We need to know what the number is before the resin to see how well the membrane is working.

Anything under 10 TDS is fine. We like it lower, but compared to what is coming out of the tap, it's great. I change my filters out if it reaches 7, if you wanted a real-life comparison.

Currently, mine is actually 0. I installed a new membrane a couple of months ago, so TDS is 3 coming out of the RO membrane, and the DI takes out the rest to bring it down to 0.