Flexible Water Tank?

[davmarwood]

On my '98 35 ft Beneteau the PO put in a bow thruster which I love when I am docking. But it was installed in what had been the forward water tank. Now we are down to 50% of original fresh water storage and the boat rides light in the bow. The orignal deck fitting for the forward water tank is still there. Likewise the filler hose and overflow which have been cut off about 2 ft below deck and sealed with wooden plugs and glue. The original fresh water supply from the forward tank to the manifold is still there also, but sealed.

Question #1: would it be advisable to install a flexible water tank of some sort in the 1ft X 1.5ft X 5ft empty cavity remaining aft of the thruster tunnel and reconnect it to the original hoses?

Question #2: if yes, what make/brand/type of flexible tank would be best for this application, and what precautions should be taken?

Thanks for any advice you can give.

[lbdavis]

I don't see what the problem would be. Your boat's designer hopefully planned for that weight in the bow, so putting it there shouldn't be a problem.

Nauta tanks are very dependable. Check them out here.

[negrini]

I used to have two flex tanks on previous boat for 3 years trouble free. Just make sure your beding is clear of debris, loose fiber, etc .. best would be if you paint the fitting place using an epoxy based. Just nominal capacity will be lower depending on bedding shape, but will adapt itself to the actual shape, with some limitation. My actual boat is short of storage as well, and just waiting commissioning to decide which and where I'll put one also. Always used Plastimo.

[Wayne25]

Search Practical Sailor for their tests of flexible tanks not too long ago.

[Rockter]

A flexible water tank lacks the one thing you need to keep the water fresh... oxygenation. Mine did not have a breather, nor do others I see.

I tried one of them once. It was fine at first, but slowly the water became rather poor, no matter how often you disinfected it.

Ultimately, I stopped using it.

Long term was our problem.

[xort]

I've ordered a Vetus flexable holding tank and it has a waste inlet, a waste outlet and a breather hose fitting. Don't know how that tank material would be for water.
I'm suprised any tank would not have a breather vent, if just for suction.