Water Filters

[billandalita]

I need advice on how best to remove chlorine from tap water onboard my boat.  I have heard and read that chlorine in the tap water will corrode aluminum water tanks such as my hot water heater.  Apparently a good charcoal filter will remove most of the chlorine.  My previous hot water tank, a Seaward, did corrode through.  My current water heater tank, a Kuuma, is also aluminum.  Should I filter the water at the shore side hose before it enters the main polyethylene water tanks, or before the water pump, or before the aluminum hot water tank?  Does anyone know which filters do a good job of removing chlorine, and have acceptable flow rates?

Thanks
Bill

[Ron Hill]

Bill : Look in WiKi, Mainsheet tech notes and search as there are a number of articles and posts written on water filters.  Most all have a charcoal filter.

I've never heard that the normal chlorine level in drinking water can hurt the Aluminum hot water heater.

[Ken Juul]

Walmart, Lowes, Ace, etc usually sell in line filters with replaceable catridges.  If you can't find one small enough try an RV parts store.  I do for the taste, but hasn't changed the life of the water heater. Mine has a slow leak, planning on changing it in Titusville, during my planned week lay over.  It lasted about 10 years.  IIRC life expectancy of most home water heaters is 10-14 years so it was not unexpected.  They work in a harsh enviornment, heated and cooled repeatedly.  Don't expect too much life out of them.

[Joe Holmes]

If it were me I'd be tempted to consider something other than the chlorine content in the water. It might be the presence of other dissolved minerals.  Some places have short lived domestic water heaters because of this. I would try the magnesium anode that Catalina Direct offers.  This sacrificial anode should keep a tank clean. Go to their website and search for anode.  They have a good explanation for why magnesium will work better than zinc.  It installs in the drain fitting.  Less than $20. 

[Mike and Joanne Stimmler]

I feel that the chlorine is actually beneficial to your tank. Your beat bet might be to put one of those filters on your sink faucet for taste. I have used a filter on the garden hose for sediment.

Mike

[Stu Jackson]

Ken and others are right, these units have a reasonably predictable life of 10 to 15 years.  When we bought our boat in 1998 the PO had just put a new one in a 12 year old boat.  I replaced it in September 2013.  It's not the chlorine.  I recommend you get in the habit of using the hot water faucets even if there's no hot water, to keep running water thru the heater and avoid any rotten egg odors.

[Ron Hill]

Bill : Stu is correct that you need to use the hot water periodically so you don't get the H2S smell, but it's caused by the PVC hoses - not the water tank or the water heater.

I found the smell was more notable in the head faucet so I rerouted the hot/cold water hoses so they no longer popped up in the engine compartment and then went around the corner to the head.  They now go from the water heater compartment, under the floor and then to the faucet attachments.  No more smell!! (also changed from the PVC hose!!)

A thought

[billandalita]

Thanks for the advice on water heaters and thoughts on the issue.  It is very interesting that the consensus seems to be that the heater will last only 10 to 15 years.  So discouraging too, since it is quite a job reinstalling one.  Runnning the hot water faucets more often seems like a great idea.  I will do that.

The Kumma heater I installed this past Spring has a magnesium anode rod.  I installed this anode since I noticed a white material almost blocking the inlet and outlet ports on my old unit. So in the interest of trying to help the heater life a bit I have scanned some of the literature and here are two interesting references on the internet:

http://www.diva-portal.org/smash/get/diva2:436113/FULLTEXT01.pdf http://www.cruisersforum.com/forums/f115/aluminum-water-tank-corrosion-42678.html

It appears from these references that the most corrosive elements for aluminum in tap water are chloride and sulphate ions and that charcoal filters are able to remove the chlorine.  Of course I would like to keep the chlorine in the main water tanks so as to keep down bacterial growth, but eliminate chlorine from the aluminum heater tank. It seems to me then that the best place to locate a filter might be before the water pump under the sink if there is room.  The filter will probably keep out other crud too.   Just some thoughts.   Bill