water polishing

[Yacht Jim]

Has anyone come up with a system to "polish" the water tanks contents. would it make sense to have this or a waste of time and money.

 

[jim rosenthal]

You could do it- a combination of a filter and UV light to make the water look better and be safer- but it's probably a waste of time and money. I had a friend years ago who believed that if you kept the tank empty and only filled it when you were using the boat, the water would stay a lot cleaner. He was probably right. He also spent a lot of time pumping the tank dry at the end of the day when he was done with the boat.

 

[Pascal]

water is free so i'm not sure i see the point of polishing it!

the key to good water is to refresh the tanks often (high turnover) and only refill with good city water which contains chlorine, this keeps stuff from growing in your tanks.

for drinking, add a good filter and ideally a UV light and your water will be safe and taste good.

When i come back home after a trip that lasted over a couple of weeks, I usually empty the tanks and refill them. I "waste" a lot of water for a few days to refill a couple times before i start drinking it.

 

[Yacht Jim]

Thanks for the help. Currently we use the tank only and re-fill about every week to 10 days. We have had a few occurances where the water had a slight tan-ish color and off taste so I thought about adding a home type filtration to the boat and think the blue light would be great. Pascal, What suggestions would you offer for make/model of blue light and best place to purchase.

 

[Pascal]

teh UV light we have is a WEDECO DLR A, filtration is a large size charcoal filter. I dont' have the filter housing nr, but here are the cartridges we use:

http://www.filtersfast.com/Liquatec-CB-450-975-10-Carbon-Filter.asp?gclid=CNP8st7O36ICFQPJsgodRxWAxg

I have to say that the water taste great! comparable to Evian and other quality spring water, MUCH better than "drinking" water

 

[MikeP]

We use a UV/filter unit for whole house water treatment in San Miguel de Allende, Mexico. The water is 100% safe and has no bad taste - some of the best water I have ever had. They are extremely effective; the light tubes/filters should be changed annually. We don't have one on the boat but if you decide to install one, the ones I am aware of use 120vac so that means that either the genny needs to be running or the unit has to be connected to an inverter when out cruising.

 

[Yacht Jim]

Excellent. I appreciate the reply and part numbers. I'll investigate the UV filter to see whats available. Having safe water out of country is a big concern as we plan our trip to the sea of Cortez. Thanks

 

[rsmith]

H2o tanks are a perfect breeding ground for all kinds of bad stuff. Dark warm and damp. The only way to safely sterilize the tank is to treat it with clorine and let it sit full for several hours and then go thru several washout cycles. a lot of bacteria that can make you realy sick is tastless and odorless. I fill my tank so it comes out the vent so any bacteria in the vent system is killed and does not recontaminate the tank as air is drawn down the vent tube as the tank is emptied. I do mine twice a year. I would do it more if I was not filling it from a public water system that has a lot of residual cl in the water.
I did some research on UV when I installed new aircond in the house after the 04 huricanes. UV effectiveness is highly dependant on type of bacteria and length of exposure to the UV light. Asw there is noway to measure its effectiveness in h2o treatment I wouldnt trust my health to it alone. After all there is a lot more UV rays from mr sunshine and still molds and bacteria grow outdoors.

 

[ron6785]

Has anyone come up with a system to "polish" the water tanks contents. would it make sense to have this or a waste of time and money.

I installed two new 15 gallon tanks in the space in the aft stateroom above the rudder posts. I run the water from those tanks thru a charcoal filter for taste and smell and then thru a 3M Model B3 which kills 99.9% of Bacteria, Parasitic Cysts, chlorine, Algae, Mold Spores ETC. This water is used for drinking and making ice. My ships water tank only runs thru a sediment filter although it could also be run thrue the same 3M filter and be fit to drink I suppose, however given how old the ships tank is I don't take the chance.

 

[MikeP]

Keeping UV-treated water in the dark before use is a critical part of its ability to do the job. UV does not kill bacteria/viruses, it destroys their ability to reproduce so they are harmless. Sunlight can re-activate bacteria's/virus' ability to reproduce.

As noted, the normal home systems are not effective on cloudy water; the water must be clear to start with. Normally the home UV systems have a series of 3 filters prior to the water passing around the UV tubes.

Here's a good site with info http://www.cmhc.ca/en/co/maho/wawa/wawa_002.cfm

As I said, they are widely used by Gringos with houses in Mexico.

 

[Yacht Jim]

Mike, This is a greatr site with a lot of information. I'm learning every day. Another question. It would make sense to install new water tanks-especially for the drinking water - but if I don't want to add more expense It sounds like I would be safe if I flush and clean the existing tank then add the filters and UV. Am I correct in assuming that I want to add these after the tank and pump ?? Thanks again.

 

[MikeP]

Yes, after the pump.

As noted, you should add clorox to the tanks and fill them so that water runs out the vents. Then use that water for the first tank so it kills all the bad thingies in the pipes. If you don't clean the pipes as well, the UV-treated water can still pick up unharmed bacteria that are in the pipes downstream from the UV. Remember that UV treatment does not add any sort of bacteria killer to the water.

 

[ron6785]

You didn't ask me , but I add my 2cents worth. The key to using your ships water is frequency of turn over. Assuming you can get the tanks clean, you should then always use the ships water tank for all you needs. That way you've got constant flow. Most of us run off the dock water bypassing the ships tank which of course is not good because your letting that water sit in the tanks for extended periods. The UV treatment is a good idea backed up by the 3M filter which kills just about everything.

You really have two problems, first the water coming to your boat has been sitting in the plumbing lines of the marina for how long??? If you have ever poured a pail of water directly out of the dock water manly times it is visibly green or some other discusting color, so you know that water contains bacteria etc. So you have to kill that stuff before it comes into your tanks. You then have to be sure the tank and lines aft of the tank are clean before you drink it. I decided to install my filtering systems aft of the tank just before the taps, icemaker etc. However because my drinking tanks are small with an overfill drain feature they are very easy to keep clean because your only dealing with 15 gallon tank.

 

[MikeP]

Totally agree - we only use tank water and use it freely to ensure a rapid turnover. We don't connect dock water unless I am working on the water system. We use a portable water softener/filter in line with the dock water for both boat washing and tank filling. I run the dock water for a couple of minutes to clear the dock pipes/hose as much as possible.