DIY Watermaker: Pros & Cons

[capn_billl]

Originally Posted by Jsta_Rebel

You're right about a DC watermaker killing your battery bank, and I've also seen membrane flow rates on this thread that caused a giggle too.. Putting together a SWRO system isn't rocket science. There are some rules that need to be followed for flow and flux rates but the rest is just simple plumbing. What I can't figure out is why people wanting to build their own RO are trying to make it DC powered and are just not using AC or running their HP pump off of the motor. It's much easier and most cruisers run their engines from time to time anyway. You can really make a lot of water quick running the pump off of the boats main engine.

Even with the downsides, I'm still thinking a DC watermaker is preferred.

1. I ALWAYS have DC, Always.
AC only when everything on the boats electrical is working perfectly.
I've had the generator crap out mid cruise several times. Sometimes I can repair, sometimes it's a part I don't have, and can't get.

2. If the watermaker makes 20 gallons a day, that is plenty.

3. Starting a 1 HP pump off of an inverter, or a smaller generator isn't a given.

4. If you want to spend the money a DC brushless motor can be VERY efficient.

5. I have 800watts of solar panels, and a 60 amp battery charger, and 100 AMP alternator. AT least one of those will be enough to run a 50 amp watermaker, even if I get multiple simultaneous failures.

6. A 1 HP AC CAT pump & motor combo is cheap, and readily available even in the 3rd world. I can always get one as a backup, or pick up a small cheap pressure washer to drive my watermaker membrane in an emergency.

[capn_billl]

I just found this meter

https://www.pfstar.com/EC-TDS-mini-c...2VDC-range-0.0

They are out of stock right now, does anyone know of a better one?

My thought is to plug a TDS meter into the output, and connect to a solenoid to automatically dump to waste until output water is good quality.

[Jdege]

https://sellfy.com/mrfixit/p/ctgo/

https://sellfy.com/mrfixit/p/tVXX/