Running freshwater through your WM, could this cause problems?

[SV THIRD DAY]

Ah, the Village Marine 19"-ers.
Each membrane is rated for a Max throughput of about 15GPH, so you are not going to be able to get more than 30GPH without risking over flowing the membranes. If it was me....I would not risk going above 25GPH total.

Normally you see about a 20/80 split when running on sea water.
20% becomes good drinking water and 80% rejects back overboard. I'm guessing you will see about a 50% split when running on fresh water. But the question is why send good drinking water through the RO in the first place? Anything below 500ppm is good drinking water from a TDS standpoint.

[autumnbreeze27]

Originally Posted by SV THIRD DAY

But the question is why send good drinking water through the RO in the first place? Anything below 500ppm is good drinking water from a TDS standpoint.

Thanks Rich. Hey you go to these marinas in Mexico and hang out with the mega yacht crews and suddenly you want to see your boat shining! Actually, I'm not going to mess with it, we're only going to PV, but it's good to know I can do it if I need to.

I did find some good metal polish in a locker and made my winches shine so bright you need sunglasses around them but my low PPM water will have to wait, I gotta work on some old cole hershey battery switches... always something more important than the fun stuff.

[Tellie]

I would recommend against what you are trying to do. Let a watermaker do what it is intended to do on your boat. There's a reason mega yachts do this, they have extremely expensive items that need to be cleaned on a constant basis. We install double pass systems on mega yachts where there is a large watermaker dedicated to just that usually in the 50-100gph range and M/Y folks tend to spend on stuff like that. Not impugning anyone's financial ability here but a cruisers watermaker should be a dedicated system. Running 100 gallons of RO water a second time through a small watermaker to gain perhaps 10-15 gallons to wash your boat may not make much sense, especially on a smaller unit like a VM200, and 19" membranes come at a premium.

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