Keeping Water Sweet

[paul323]

Hi folks,

My new boat has two 19gallon water tanks. I was wondering - what do you do to keep the water sweet? I know some recommend adding chlorine/bleach (very diluted), and interested in advice before they go green....

I did search the forums - sure I saw a thread somewhere - but with no success....

[DwayneSpeer]

Add a water filter and drinking water tap. Use unfiltered water for washing, etc. Adding bleach once a season just prior to use or when putting away for the winter is a method to help assure the tanks are clean, not sweeten the water for drinking. With the bleach you need to let stand a few days and then flush out completely.

[CaptainForce]

.......or using it works. If you "turn it over" at a regular rate it will stay good. Take care and joy, aythya crew

[Omatako]

If your tanks are dark (not white plastic), the water should stay good for a long time without going bad. Light makes water deteriorate. We can and have carried 1000 litres of water which has lasted several months without any treatment and the water was still good at the end.

I guess though that it depends on the start point - how good the water was when it was put in.

But there are folks that filter the heck out of water and that works for them too.

[sailingdog]

One thing that will help is putting a filter on each of the vent lines to the tanks. A majority of contaminants come in via the vent lines—mold spores, pollen, dust, etc., and adding a filter to the vent line eliminates most of this.

I'd also point out that if you are shock treating your water tanks, you really don't want or need to let the bleach sit in the tanks a few days as previously suggested. That is really unnecessary and really a bad idea if you have aluminum water tanks.

From Peggie Hall's instructions:

l Fill the water tank with a solution of 3/4 dl. of household bleach per 10 litre tank capacity.
Turn on every faucet on the boat (including a deck wash if you have one).
Allow the water to run until what’s coming out smells strongly of bleach.
Turn off the faucets, but leave system pressurised so the solution remains in the lines.
Let stand overnight - at least hours - but NO LONGER THAN 24 HOURS.
Drain through every faucet on the boat (and if you haven’t done this in a while, it’s a good idea to remove any diffusion screens from the faucets, ‘coz what’s likely to come out will clog them).
Fill the tank again with fresh water only
Drain again through every faucet on the boat, repeating till the water runs clean and smells and tastes clean.

Remember: cleaning out the tank addresses only the least of the problem ... most of the problem occurs in the lines, so it’s very important to leave the system pressurised while the bleach solution is in the tank to keep the solution in the lines too.

She also points out the necessity of keeping the water flowing through the system by using it regularly and frequently.

[paul323]

Hmmm...my tanks are plastic, but normally away from light - I guess the best answer is, like everything else in a boat, if used regularly it should be fine....

Vent lines - should have thought of that - good tip.

Dang - should have thought of Peggie's advice! I'll have to get her book, as her advice always seems sound.

Thanks!

[jarcher]

A well timed thread for me. I mostly just race my boat, and as such never fill the water tank. For drinking we bring bottled water and I don't want the extra weight.

However, my wife today complained that there is never any water on the boat for washing. So my project for this week is cleaning out the water tank. I'll probably just replace the lines, since they are short and came with the boat.

What got my attention is when SD mentioned "vents." I don't believe my tank has any, which is probably not possible, since when water comes out I guess air has to get in somehow. If I have to add them, what do I add? Are they just lines from the top of the tank out? Do they have any special fittings, like a one way valve or anything?

[sailingdog]

A vent line usually comes from the highest point on the tank and usually has a through-hull fitting that has a screen on it to prevent insects from nesting in the line.

[ffiill]

Will have to do mine-low turn over and 80 gallons!-

[SlowButSteady]

Originally Posted by Omatako

... Light makes water deteriorate...

Huh? Into hydrogen and oxygen? I don't think so. Light will allow growth to form in you tank, but the water doesn't "deteriorate".

I add a cap-full of bleach every time I fill my water tank (20 gal) to keep the biological activity at bay (it's a white HDPE tank, but it's in a dark locker). That keeps the water potable, albeit with a slight chlorine taste right after aI fill the tank. However, I normally only use the tank water for washing. For drinking/cooking I buy those little 2.5 gal carboys of water at the grocery story, and keep a stash of San Pellegrino in the ice chest.