Visit our Popular Forums

BothFeet · 17-06-2016, 11:02

I've got 2 100galllon fresh water tanks on my 2000 Leopard 45. There is a valve under the sink that is SUPPOSED to allow me to switch tanks. I've never been able to get it to work. The pump sucks air and I cant get the hose off the fitting to try and attach another pump to prime the line. I may keep fiddling with it until I figure it out but had a thought occur to me: what if I plumbed a line with a valve in the middle at the bottom of the two tanks...between the two tanks? It would keep a balanced load, not that that's hugely important, but I would have all 200gallons available. With the valve I could segregate if I needed to.

I do have a watermaker but it's pickled for now since I'm up a river in North Carolina.

So tell me the reasons I shouldn't do this? safety/reserve I know.

If you have similar experience, tell me what materials you used?

Thanks!!!!
S

**JPA Cate** · 17-06-2016, 16:38

If you have deck fills and the O-rings wear out, if you contaminate one tank with dirty fresh water or salt water, it will travel to the other and ruin both. It is easier to clean up one tank and all its hoses and vents than it is two.

Ann

BothFeet · 17-06-2016, 16:40

Both tanks fill inside the locker, butnyour point is valid.

Capt Phil · 17-06-2016, 17:02

Not something I would recommend because if you contaminate one tank, you have contaminated both. I suggest you have independent valving where you shut off one tank if it is dry and switch to the full one. Plumb your water maker so you can fill either tank but not both at the same time. Your water maker should be valves so if your tank is full it will flow overboard. Phil

Ulstue · 18-06-2016, 08:56

Sorry if this goes in the wrong direction: After switching the valve from one tank to the other, it is normal that the pump needs a time, and that there are problems with air in the hose. These may need a time with a faucet is opened while the pump is working, so that the air can get out.

lordgeoff · 18-06-2016, 09:06

I had heaps of problems with my 4 water tanks. In the end I just needed to take the inlet and outlet and breather hoses off, clean the pipes and use new clips tighten the hoses onto each pipes. The water pressure system hates sucking air from any connection just like a Diesel engine.

Pieter · 18-06-2016, 09:08

On my FP40, i have the tanks connected, however only one external filling point and my watermaker fills only one tank. I have a valve in the connection tube so i could isolate... I never do that, for some practical reasons:.. the access to the valve is rather cumbersome (as is access to the actual tanks; cant really clean them easily unless i take them out which i have never done btw) and so keeping them connected i maintain balance and dont have to worry abt it. I live already 8 years on board, and never had any contamination issue.

Best rgds
Pieter Kommerij
SV Lumina
Lumina Charters – Brazilian Coastal Catamaran Sailing

**Tellie** · 18-06-2016, 09:32

It's not unusual if one tank runs dry that when you fill it back up that it is tough to re-prime, many times these pumps won't self prime at all. Cross contamination between two joined tanks is certainly a concern especially if you are cruising far from easy water access. It's better that the tanks feed to a valve controlled manifold so both tanks can be isolated from one another or you can have both feeding the house pump at the same time. And as Capt Phil suggests, make sure your watermaker is plumbed with a 3/way valve so you can fill each tank individually.

Halden Marine Services – Marine Watermakers, Solar Panels, Wind Generators

MerlinBrasil · 18-06-2016, 10:04

Water being a critical aspect of life, for a catamaran doing blue water, is it not logical to have two watermakers, one for each hull and tank?

I'd go with the same make and model to maintain same spare part inventory.

Make sense, financials aside, to anyone else?

Regards,
Merlin

Maka · 18-06-2016, 11:37

It is important to have more than one water tank and more than one fuel tank, and keep them separate.
Contamination is the issue. Especially if you are cruising and use different sources to fill either or both.
A contaminated water tank could be used for wash downs only until it is empty.
Contaminated fuel is another matter.

A single water maker is more practical than two. Cost and space are the issues here. Easy to plump it for multiple tanks.

Just my opinion.

Tomaz473 · 18-06-2016, 12:19

Quote:

Originally Posted by MerlinBrasil

Water being a critical aspect of life, for a catamaran doing blue water, is it not logical to have two watermakers, one for each hull and tank?

I'd go with the same make and model to maintain same spare part inventory.

Make sense, financials aside, to anyone else?

Regards,
Merlin

To me it does not make sense.
1) Watermaker must be run regularly, if you have two you have to run two of them.
2) Twice the price
3) Twice the space needed

To me Water-maker is not essential safety equipment - it is something to make your life easier like a fridge or music.
For a passage I always start with my tanks full. Then I run watermaker as needed to top up what is used. Life is good, we can take showers, . . .
In case water-maker would brake we would resort to water-conservation mode. No big deal, we would reduce usage for cooking and drinking only.
Our back-up plan (no water-maker) is what many people have anyway.

Jd1 · 18-06-2016, 12:44

There is a simple (but crude) way to get your pump to prime when you switch to the second tank - suck on the faucet. Seriously, put the faucet on cold, open it up and suck on it. Before you know it the pump sound will change which indicates that some water is starting to make it through. At that point you remove your face and leave the faucet open until all the air clears which might take 30 or so seconds. In my case I have yet to receive a face full of water as it is very clear when the pump starts to see some water which is well before any pressure develops.

Rustic Charm · 18-06-2016, 15:45

I have two plastic valves in the middle of my boat and my deck filler goes to these and not a tank. Each of my tanks can be either shut off completely or opened and filled together. Depending on how I've loaded the boat will depend on which tank I use first.