[DAVID HARRIS]

I have acquired a merlin RO system with 3 filters 1 carbon filter and 2 RO membranes. I have replaced all filters and had it running for 4 hours. My TDS reading from my tap is 170 water pressure is 55PSI it is making 1.3 litres a minute of pure water with a TDS reading of 13. Is this the best reading I can expect or if I fit a pre filter either a 5 micron sediment or a water softener will this help to lower the TDS from the system. Thanks for any help

[sunshine windows]

Booster pump might help reduce the reading

[The Jester of Wibbly]

Sound right for a merlin.  It reduces tds by 90% as a rough guide. You need Di resin to finish it off

[DAVID HARRIS]

Hi yeah I have a DI bottle but as you know the lower the TDS the longer the DI beads will last. Cheers

[Spruce]

Hi yeah I have a DI bottle but as you know the lower the TDS the longer the DI beads will last. Cheers

You are right there.

Unfortunately the Merlin is being used for something it wasn't designed for originally. It was designed as an under counter r/o unit for American kitchens. The water needed to be pure, but not that pure.

Merlins use a lot of water to produce a little pure (6 liters for 1 liter of pure) with an out the box efficiency of 90% as Paul Wibble has already noted. A fellow windie has had 2 of them and another sold his on Ebay and bought a 4040. All ran/run with the same pure to waste ratio and the same efficiency.

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