Making fresh water from sea or brackish water is turning out to be kind of fun.
Our water tank is getting low, so I fired up the water maker. This is only the third time we’ve run it for a good length of time, and figured it was time to make sure things work well.
We’re on Shore Power at the moment because we’re in the marina. Tide has hit high tide at about 8:15 this morning, and flowing out now. I was trying to get this done at high tide to prevent pulling in mud or silt from the floor of the ICW. The water is brackish.
So about 9:25 we fired up the rig, I adjusted things so it is creating water and running at 21 gpm. The contaminate level is at 110 most of the time so far.
We’re running it for slightly less than three hours today to fill the tank and to ensure no problems are found.
No leaks. No problems thus far. It’s been going for just under two hours. Should take three to fill the tank to capacity.
The ICW is flowing out right now at around 2.5 knots of current and I really wanted flowing water going past us. Helps eliminate standing muddy water and stuff floating near by the intake. Keeping a constant flow of water is a good thing.
Checking the strainer shows the incoming water is clear, nothing of note in it, no critters I can see and no debris or dirt.
The main filters are clear, with a small amount of “dirt” showing in the first filter (20 micro filter).
My only issue is that I don’t know the quantity of water in the tank. We normally fill with a hose or using water cans, and when we reach ‘full’ the tank will make a popping sound. I don’t think that is going to happen this time.
I suspect I might have to install a gauge of some sort or a see-through tube to the tank to let me know my levels. I’ll ponder that another time. I know though, when we hit “full” the vent will begin to vent the extra water into the bilge so that will be my indicator for the time being.
My friend Kevin, when I told him about the installation walked over to the garden hose by his boat and picked it up saying, “I have a water maker too”. Kevin has been sailing his whole life, and I know he probably understands the difficulties of getting fresh water in some places. Others know that throwing money at a problem offers a temporary solution, like just purchasing the water.
I prefer self-sufficiency over total dependence on others. Sure, I still have to have electricity, and to get it I have to run a generator. But a gallon of gas will run the generator for ten hours or so, producing 210 gallons of water if I ran it the whole time.
Gas (here) is about 2.89 a gallon. Water is free.
In the islands, gas is more, and the water isn’t free. Unless you catch it from the rain. Which we can also do. Right now, gas is about 1.20 dollars a liter in the Bahamas (roughly). Water is running from 6-7 dollars a day to as much as $20 to fill your tank. Since the hurricane went through, I don’t know what they are charging at the moment.
Options….. we all want options.
A gallon of gas in Bahamas is about $4.80 so, still slightly cheaper to produce the water using the generator than to purchase it and haul it back back forth in the dink to me. Less work too. I HATE pulling into marinas and running the engine constantly. So… to me, it’s a convenience thing.
As I’m typing this, we’re right at two solid hours of running the system. The noise isn’t too bad and the unit is under the settee. I open it up for air (motor can get warm) so it’s a little louder that I like, but tolerable.
We should have produced 42 gallons of water at this point, and my vents aren’t yet venting water, so that’s good. The bilge doesn’t have any water in it at the moment either. So that’s good too. Contaminants are at 117 ppm. Still good.
Just as a refresher here, pure sea water should produce fresh water, at about 200 ppm. Less than pure salt water will produce water at lesser numbers. (We have seen it from 65 – 120). I think the difference is whether the tide is rising or falling.
If rising, then mostly we will see fresh river water coming back into the ICW from the Cape Fear. As it rolls out again, it will be more saline from having mixed with the incoming sea water from the tide.
If we ran clean water through (that might be high contaminates) it should run much less than the 85 number above. The FDA says about 600 ppm is ok for human consumption. A chart is provided below.
By the way, our drinking water goes through a Seagull Carbon Filtration system at our galley sink. Most of the time the water coming out of the regular faucet is fine, has no smells and tastes ok. We use the filter system for the fresh water, just in case.
Our tanks (now singular) are treated about about every three months with enough bleach to sterilize the tank internally and the hoses. In general, I’ll open the tank faucet to allow water flow, run the hose into the input (on the deck) and run it for awhile to ensure flushing the tank. Then add the chlorine, and flush again in a couple of days. I usually flush most of that water through the bilge to keep it clean as well after a couple of days. Most of the chlorine is dissipated by then.
The water maker needs to have the system flushed every few days as well with fresh water, which is also run through a carbon filter to remove chlorine (and typically, I just connect a garden hose straight from the shore power pedestal to clean the filters and the Reverse Osmosis (RO) filter.
At exactly 3 hours in (I knew the tank was almost empty) the system started blowing water into the bilge, indicating the tanks are full. I brought the system pressure down and turned off the main pump motor, allow the lift pump to continue for a few months, then powered it down. Now, I have the garden hose attached to the carbon input filter, and am flushing the RO out.
So, there you have it. Our first solid, real production of water from the ICW with our new water maker, filling the tanks, tasting, drinking it and using it. I’ll let you know if it kills me. HA!
The water, by the way, coming through the system is clear, sweet and has no smells or odd tastes. I consider this a success.