View Full Version : Water purification products

02-19-2014, 09:29 AM
I only have ~140 gallons of fresh water onboard when I leave the dock, not counting the hot water heater. I have run out of water while anchored over a long weekend and even when the dock's water lines were down on occasion.

This has me thinking about ripping out my holding tank and installing a fresh water purfication system on the boat to ensure I'm never without fresh water again.

Does anyone have one of these systems onboard? Please tell me about your make / model and your experience with it. What's the operating costs of these systems?

I've looked at The Water Fixer, which is a site sponsor, but they have no installed pictures of the system anywhere on their site. I'm not sure of the clearances and if my boat affords them. What's more, the maintenance costs look pretty costly! The filters don't bother me too much, but replacing the light every 2 years will run $300!

02-19-2014, 11:23 AM
I have such a system and love it. I liked the water fixer system, but ended up having to make my own to address the very issues you raise. I didn't have room for their pre-made system so created some flexibility by installing separate components. That helped a lot since the components don't need to be all in the same place.

There are three basic components of about any system. Here they are in order.

Before you get to your system, you will need your standard pick up tube, pump, screen strainer, and probably a pressure accumulator tank. Since that's most likely already on your boat, I won't bother describing them unless you tell me you need it.

Step 1 - Sediment Filter
After your water comes out of your pump, you need to take out sediment. I do that with a Pentek 10" big blue filter housing. The housings are about $40. The "big blue" part refers to the diameter which is about 4.5". At my lake I need that big a diameter to make room for the sediment that tends to cloud water. There is a big blue filter housing that's 20" long, but I didn't have room for that in my boat. If you have that kind of room, I would get the 20" length. Here is what my housing looks like:
I tried several different filters in the 10" big blue housing and settled on a pleated 5-micron sediment filter. The filters cost about $5 and last me all season.

After step 1, the sediment filter, I tee off the line coming out of my sediment filter to supply most of the water needs on my boat. This includes toilet flushing, dish washing, and showering. I am fine doing these kinds of things with lake water filtered to 5 microns. Because it tees off before it gets more filtration, the 5-micron filtration is all the filtration I give to water for the uses I've listed.

Step 2 - Carbon Block Filter
While I'm fine washing dishes (except for the final rinse) and flushing toilets with lake water, I don't want to drink it without more filtration. Unless I use some kind of carbon block, my water has what I call a "swamp water" taste as if you're drinking tap water in South Florida. Even if it were okay to drink, the taste is nasty. A carbon block filter takes care of that nicely. The carbon filter elements are a little spendy, so I went with a standard diameter housing. They are about 2.25" in diameter and 10" long. Some manufacturers call them a "slimline" housing. Mine looks like this:

I experimented with a lot of filters to find what works best for me. I settled on a 1-micron carbon block. If I buy them by the case, they are around $10 each. Depending on how dirty my water is, I can go through one of these as quickly as one per trip or they might last a month or so. One micron is really small - smaller than bacteria. The only thing I don't know anything about would be heavy metals since we don't have any of those at my lake.

Step 3 - UV Light Treatment
Even though filtering to one micron eliminates most bad things like bacteria and Cryptosporidium, it doesn't touch really small stuff like viruses. For that, I treat my water with UV Light. I settled on a Sterilight S2Q-PA/12volt unit. They look like this:
It uses very little power (22 watts) and has a nice-looking stainless steel housing. You're supposed to replace the lamp every 9,000 hours. That would come around about once a year if you were using it 24/7. I don't get to my boat that often, so 9,000 hours of use would take me about a lifetime to accumulate. I do clean the lamp's quartz housing at the start of each season and I will likely replace the bulb after five years or so even though it won't be anywhere near 9,000 hours. The whole unit was about $300. If memory serves, a new bulb costs about $50 or comes in a kit with a new quartz housing (a clear tube that the light sits in) for about $100.

The water that goes through my full system is just what I use for drinking, making ice, final rinsing of dishes after their lakewater wash, and things like brushing teeth. I just make it as I use it, so it stays fresh. It comes out of a "candy cane" dispenser next to each of my sinks.

The nice thing about making a system with separate components is that the components can be at various places around your boat. You just run something like 1/2" pex line between the components. Naturally you use other fittings to attach the pex line to your components. You will also need mounting brackets for each of the components. I spent under $100 on all my brackets, fittings, and related items.

You don't have to do an on-demand system like I did. You can get by with a lower-flow system if you are using it to fill your existing water tank. That might work well, but I prefer to not have treated water sitting around before I use it. One additional modification I made was to drill and tap a drain on each of the filter housings and to weld a drain onto the bottom of the UV unit. That makes winterization easy.

I am going on my third season with this system and no one has had even a tummy ache. I think I spent about $500 putting the system in and I spend about $100 a season to buy filters and the like. But having unlimited fresh water is, as MasterCard would say, priceless.

02-19-2014, 12:20 PM
I have seen several setups like the one Endurance built above. The people that have them seem to be happy with them.

I have 360 gallons of water and have never run out - even spending 10 nights out. Where are you using all of your water? - long showers, dish washer, ...

02-19-2014, 01:00 PM
Wow Endurance! Thanks for that info!!

I never considered building my own, but it sure makes food for thought! I have 2 water inlets used for my toilets in the exact compartment where I'd set this system up and I already have electric (12V and maybe 110) there. I could hook both toilets up to 1 inlet tube and use the other for the boat's fresh water intake. Problem is, I won't be able to seperate my water use like you did. Each faucet will be tied into the same system, so I'll need to filter a lot of water, whic would be a lot of filters!

E.TN - After a long day of swimming in lake water, each of the 4 of us wants to take a quick shower each night. The wife calls me "The Water and Electric Nazi" on the water! :)

02-20-2014, 03:36 PM
I would keep the existing tanks, though, even if you leave them empty. Save yourself some work, and it might matter to the next owner.

02-21-2014, 05:08 PM
You might want to consider keeping your existing tanks but filling them with water that you purify. Even a small-capacity system makes about a gallon a minute. You could run it for an hour first thing in the morning and make 60 gallons. At an hour and a half you'd be pushing 100 gallons. If you did that, you could leave all your plumbing intact with the exception of teeing off to flush your toilets with lake water. If you did decide to run water to "candy cane" dispensers at each sink, pex line runs easily. That would also leave your existing plumbing pretty much intact.

02-23-2014, 03:21 PM
Talk to Sailabration. They build them. That's what we have on our boat.

02-24-2014, 06:39 AM

Do you guys actually drink the water the system produces?

Do you have a freshwater holding tank aboard?

Do you winterize the system?

02-24-2014, 07:12 AM
I normally keep bottled water for drinking but my husband drinks it and I have on occasion. We do not have freshwater holding tanks. We decided to go with this system instead. We do not winterize instead we keep a small heater in the pontoon during the cold months. I know of another Sailabration owner that added a freshwater system to his boat after it was built.