Filtering rainwater

[Kelpie]

Have a look at this

Clic & Fill - Navy Clic EN
I don't have one and think yours might be one of the very few occasions it could be useful.

That's pretty clever!
Our deck filler is almost flush with the deck, so a fitting like that would be useful anyway.
At some point I will replace the deck filler cap and build up a little plinth for it.

Fwiw we collected water in buckets and jerricans, then transferred it into one of the main tanks through a simple gauze filter. Always used only the same tank (of three).

We've spent the last two years collecting rainwater in jerry cans. At first, it was kind of fun to spend an hour swapping over cans and marvelling at how fast they would fill up. But I'm a bit over that now and just want to be able to stay down below and watch the tank full up

Also, we are not on the boat 24/7 and it's frustrating to be caught out ashore in a downpour knowing that all we're getting is 25l, and that's if we remembered to hook up an empty can before we left.

 

[rogerthebodger]

Geem

1" PVC ball valves are very cheap and either a little bit of domestic plumbing PVC pipe and PVC fittings would make a very cost effective diverter system as there would be no pressure

We also get very heavy rain storms on the north coast of South Africa

 

[noelex]

Have a look at this

Clic & Fill - Navy Clic EN

Be careful attaching pressurised water (from a dock supply) directly to a tank without an air gap. Water tanks cannot typically survive pressurisation above around 5psi. This is not surprising. If a tank wall is 4 sq feet in area, 5psi will produce a force equivalent to almost 3,000 lbs.

While the tank will be vented, the vent size is typically small. Attach the tank directly to 30+ psi domestic hose and the pressure in some cases will reach damaging levels. The device is fine for gravity fed rainwater, but risky for filling a tank via a dockside supply (unless it vented in some hidden way).

 

[Roberto]

Be careful attaching pressurised water (from a dock supply) directly to a tank without an air gap. Water tanks cannot typically survive pressurisation above around 5psi. This is not surprising. If a tank wall is 4 sq feet in area, 5psi will produce a force equivalent to almost 3,000 lbs.

While the tank will be vented, the vent size is typically small. Attach the tank directly to 30+ psi domestic hose and the pressure in some cases will reach damaging levels. The device is fine for gravity fed rainwater, but risky for filling a tank via a dockside supply (unless it vented in some hidden way).

Yes of course. I personally would have no use for that device, though I see a number of people using it, trusting the excess water would flush through the vent (maybe clean them as well).
Summer '22 we had very serious water restrictions (basically only for filling tanks, no washing of the hull, no rinsing sails, etc etc), a boat near mine attached the hose to that thing and forgot it, he went for a walk: as he came back water was copiously coming out straight from two vents with great splashing noise over the water surface, marina personnel rather upset, owner very embarassed

 

[rogerthebodger]

I have a direct water connection from the marina tap into my fresh water system that bypass my tanks and pressure pump that I can use when on my home mooring

I found that that sometimes if the supply water pressure was too high that the PRV only califier would open and leak

I then made up a water pressure reducing valve to stop this opening of the PRV

This type of pressure reducing valve could be included into the tank pill fitting proposed

 

[Sea Change]

Update:
(And yes, I'm the OP, I got locked out of my old account, grrr)

I installed a fitting in the outside of the coaming, I think it's designed for a cockpit shower or similar. Anyway I mounted a garden hose type quick connector inside it. When not in use, it has a cover which will keep it protected. Our dodgers extend along the coaming so it's a good location.
I couldn't quite bring myself to cut an 80mm hole in the boat but the Eberspacher exhaust was in about the right place anyway so I just removed that and used the hole (we haven't needed a heater since we left Europe, and it's no longer connected up).
A 3/4" hose goes from this fitting down to a standard 10" filter housing in the bilge, which has the 1 micron filter in it. From there, I teed in to the breather line for the water tanks.

And the verdict?
It's brilliant. Must count as one of the best upgrades I have made to the boat. The water is clean, and we have been getting enough rain recently to keep the tanks full most of the time. It's a nice feeling to have the rain start and think 'oh good, that'll top up the tank!'.

I think I'll abandon my watermaker project and sell off the bits. I can't really be bothered with the hassle and expense of running one. This is obviously location dependent- rainwater collection wouldn't be much use in the Med (but dock water is cheaply and easily available most places).

 

[nathrebel]

I have been a liveaboard for the last 8 years. prior to that i live a van, caravan and horse drawn gypsy wagon since 2013. i have always used rainwater with a simple coffee filter to catch bits. the water i found a lot better than any tap water and have never gotten ill from it. The traveller liason officer had my water tested once and it came back cleaner than tap water for that area (SW). you must understand to keep the surface your collecting from as clean as possible. i used to clean the canvas and roofs with old washing up/ shower water at least twice a week. one other thing is to work out the volume of water your surface needs to be complerely covered, then add 25% extra. this is waste water for the first rainfall this is the amount you need to waste before collecting it to comsume/wash. the reason is this will clean the surface your collecting from, i used a 5 gallon bucket to fill before i started to collect it for use.
also make sure you collection containers are solid colour so sunlight cant get through this will stop a build up of algae. also i would not hold water for to long and always had a few 5l store brought water bottles stored for emergency