Originally Posted by cburger
1 Is it possible to have a watermaker
that can be run from polluted riverwater, the boat is on the Hudson
and would like to have a system set up that can reliably make clean potable water from any type of area, not just pristine in the middle of the ocean locations, (If that even exists anymore). I know that municipalities make drinking water
as well as us microfiltration for the final process on wastewater and protect the membranes with some form of pre-filtration, (Activated carbon maybe). Is there any type of prefitration systems suitable for small sailboat suitable watermakers that will allow water production in potentially oil
[[In full disclosure I'm the owner of www.cruiserowater.com
so I make and sell water makers. Just to be open in the event you didn't know.]]
There is this myth out there about water makers that you can only run them in crystal clear blue water. Never in anchorages
, never in a cloudy or merky water and certainly never in a River or brackish water estuary.
If it was true that you can only make water out in crystal clear blue water then most cruisers would never make any water because we spend 90-95% of our time out cruising AT ANCHOR
. With a good prefiltering system of a 20 micron followed by a 5 micron prefilter you can make water in dirty looking water...the killer is Oil
and Diesel fuel
...but particulate solids will be removed by the prefilters. Sure you will need to wash out and change out your prefilters more frequenty than out in crystal clear waters, but to me that is better than water rationing, jerry canning, or pulling anchor
just to make water. At $7ea for a prefilter that can be cleaned 4-5 times before replacing, I don't stress over making water in green or even brown looking bays, anchorages or even estuaries.
You can't use an Activated Carbon filter as a Sea water prefilter...well I guess you could be it would be dead (or fully loaded) in a few minutes but there really isn't chlorine or oxidants in sea water anyway to hurt your system. Where AC filters are unsed in water makers is to remove any oxidants (specifically Chlorine) from the tank water used for fresh water flushing
the water maker.
When you are in a river or brackish water (less "salty" than pure sea water), just adjust your water makers operating pressure down from about 800psi and let your product water production rate be your limiting factor and make all the water you want. You don't want to significantly exceed your rated flow rate or you can damage the RO Membrane.
My recommendation is to talk driectly to the different water maker compaies out there because how they answer your questions will tell you as much about them as their answers. I do that test with any gear
manufacturer these days because you would be surprised at how many companies give poor service
even BEFORE the sale
, so once they already have your money
, will they actually improve their service
I Oily water is a real concern, that will KILL your membrane's organic seperation layer...so you will need to install an Oil/water seperator prior to your frefiltration system. These are pretty standard devises on commercial
larger systems...but honestly, most cruising boat don't use these due to the additional ppressure drop they add to the system.
In terms of system footprint. Here are a few photos of water maker installation
on boats. Now these ARE 120v AC systems so it would require either a honda
genset, but the photo
will give you a footprint idea:
20 GPH Water Maker in V-Berth of 35ft boat.
30 Gallon per hour water maker in 40ft Cat
20 Gallon per hour water maker showing boost pump, prefilters, and then the Activated Carbon filter that is used for fresh water flushing