Distilled or RO?

[capta]

Well, we've got the watermaker up & running. Of course it's making way too much water for the two of us to use (boo hoo), but my girl friend asked me today if we still need distilled water for the batteries, or can we use the RO water?
Caught me a bit aback? Why not?
Running at just under 800 psi, making water that is 225 (or less) ppm TDS. One would think there would be that much TDS in distilled water by the time it's bottled? We've plastic tanks, cleaned twice since the H2Omaker, but I can get it before the tanks, easily.
Any thoughts?
Thanks

 

[justsomeguy]

I'm betting distilled water has fewer dissolved solids than RO. That said, are you within easy reach of distilled, or out at sea? Could you distill your own?
I'd use RO if I had to...

 

[jepomer]

Running at just under 800 psi, making water that is 225 (or less) ppm TDS. One would think there would be that much TDS in distilled water by the time it's bottled? We've plastic tanks, cleaned twice since the H2Omaker, but I can get it before the tanks, easily.
Any thoughts?
Thanks

225 ppm TDS is just about as pure as "tap water" and it would ruin the battery. The TDS would need to be in single digits to be equivalent to bottled distilled water.

Reverse Osmosis (RO) is a great technology to remove things from water. But it needs high pressure and a long run time (tens of minutes) to begin to reach the 95 to 99% rejection levels. The water makers for boats and under-sink setups are fine for drinking water. But they are inadequate to reach "pure" water levels.

My day job is working with high purity water used in medical and pharmaceutical applications.

 

[tommays]

MY tap water at work runs between 65 and 185 TDS depending on season and would kill any battery

My pure DI water at work is .05 TDS or less and if all the resins are brand new sometimes its so low the machine cant even do a reading for a bit till it gets a bit tof dirt

 

[capta]

distilled vs RO

Thank you all very much. I stand corrected & have learned something.
It's just so exciting to have an unlimited supply of water on a small craft that I feel like the RO unit is all powerful. As many showers a day as I please? Unheard of when I circumnavigated in the 70's; we had to wash dishes in salt water. Back then, in a new port, a long hot shower was a much nicer invite than a meal, drinks or a scenic tour. Next step; a washing machine! Boy, RO, GPS, wifi, what will they think of next? Pretty soon I'll be obsolete, and the equipment onboard can just take the boat from one repair place to the next.
Thanks again,
Andrew & Nikki
S/V Skipping Stone
F de F, Martinique FWI