Placement of (fresh)water filter?

My freshwater flow has been steadily decreasing since I purchased my boat. I have a replacement pump ready to install, and got a new filter *and* housing to replace the one which was (weirdly) installed. (Some iron fittings at either end of the housing, gack.)

The original location is directly outboard of the freshwater pump, and the filter installed dramatically decreases water pressure, per the manufacturer. I selected a different filter, but I'm wondering if I would also be better off filtering only the galley water. The filter and housing are a nice compact 5" high, so under the sink would work.

Any thoughts and prior experience welcome, thanks.

Bob

Galley water only is an OK idea, but I never saw the need to filter the water. Do you filter the water at home? The Bay Area, and EBMUD has a pretty good water supply. What are your water tank(s) made of and have you had a look inside them?

aenlic said:

My freshwater flow has been steadily decreasing since I purchased my boat. I have a replacement pump ready to install, and got a new filter *and* housing to replace the one which was (weirdly) installed. (Some iron fittings at either end of the housing, gack.)



The original location is directly outboard of the freshwater pump, and the filter installed dramatically decreases water pressure, per the manufacturer. I selected a different filter, but I'm wondering if I would also be better off filtering only the galley water. The filter and housing are a nice compact 5" high, so under the sink would work.



Any thoughts and prior experience welcome, thanks.



Bob

Click to expand...

I would definitely do galley only. Unless you are filling your tanks with toxic sludge, the water you drink and cook with is the only water I would filter.

FWIW, the boat we bought has a filter on the galley sink and it has worked well.

I have a 10 micron debris filter ahead of my domestic pump. We use tank water only in the boat filled with city water from the dock.
The filter is clogged at the end of the short New England season.

I built this monstrosity last year. We are filtering water for the whole boat. Hot and cold. It was just easier for me to do it this way (and a nice project). There was more room in the engine room for filters, and it was easy to re-route the existing plumbing. The first filter is a 5 micron sediment filter. The second is a .5 micron carbon filter. I was concerned with a loss of flow with the .5 micron filter, but that has turned out to be a non-issue.

Water Filters

This year I started filtering the water going into the tanks. This method is much easier than the whole boat filter I had been using and seems to be more effective. I haven't cleaned a faucet outlet airator of scale, etc since using the hose filter and we are living aboard using the tanks and boat water pump. I bought a two pack of these filters in the rv section at Walmart, but any rv retailer should have them. I added the inlet hose section for easy accessing the docks potable water faucets.

jleonard said:

I have a 10 micron debris filter ahead of my domestic pump. We use tank water only in the boat filled with city water from the dock.
The filter is clogged at the end of the short New England season.

Click to expand...

Thanks, Jay. I'd decided to filter all the pump outflow, based on the state of the filter I'm replacing, as well as the fact that I'll often fill the kettle or a pan from the hot water spigot to save time to get to boiling.

I'm surprised that neither my local chandlery nor West Marine stock the filters for compact (5" tall) filtration housings. For an extra $12, I replaced the white Culligan housing with a clear one from Pentek; that will permit visual assessment of the filter's GI (Grossness Index). ;-)

aenlic

Rusty said:

I built this monstrosity last year. We are filtering water for the whole boat. Hot and cold. It was just easier for me to do it this way (and a nice project). There was more room in the engine room for filters, and it was easy to re-route the existing plumbing. The first filter is a 5 micron sediment filter. The second is a .5 micron carbon filter. I was concerned with a loss of flow with the .5 micron filter, but that has turned out to be a non-issue.

Click to expand...

Nice! If I may risk a comment, I would have added a bypass on each filter so I could still have water in case of any issue or dirty filter without readily available replacement part.

L

Y or Y? Adding a Y valve!

Lou_tribal said:

Nice! If I may risk a comment, I would have added a bypass on each filter so I could still have water in case of any issue or dirty filter without readily available replacement part.

L

Click to expand...

I'm glad you mentioned that just in time for me, Lou; I'd thought of that, as I was used to having it on my whole-house filter, but in the heat of final installation had lost the thought.

I'll have at least one trip to the chandlery for necessary parts, will include shutoff or Y-valves as part of my installation.

Thanks!

aenlic

Lou_tribal said:

Nice! If I may risk a comment, I would have added a bypass on each filter so I could still have water in case of any issue or dirty filter without readily available replacement part.

L

Click to expand...

My bypass plan is to simply remove the element if necessary until I can get a replacement.

jleonard said:

My bypass plan is to simply remove the element if necessary until I can get a replacement.

Click to expand...

That's what I just had to do, we're out cruising right now, the cold is filtered the hot not, try adjusting the temp in shower with a very small amount of cold flow compared to hot, not fun.

My bypass plan is to simply remove the element if necessary

Click to expand...

That is my plan at this point as well. We carry two spare sediment filters and one spare carbon filter. Removing the filters or re-routing the plumbing is a short process.

But building in a bypass sounds like a good winter project.

We filter all the water supplied to galley and head (including the Raritan Marine Elegance throne). I changed the routing of the dock water so that it, too, is filtered. Pretty typical 10" filter similar to this except that the bowl is clear plastic: https://www.filtersfast.com/P-Culligan-RVF-10-RV-Filter-System.asp

No doubt plenty of crud in our 33 year old tanks, certainly plenty of crud coming down the dock. We no longer carry bottled water.

We had installed a small under-sink filter on the sailboat but it quickly filled the filter. We installed a large under-sink filter in Philadelphia and it has a dedicated spigot. It's only used for Sue's tea and our iced drinking water.

Rusty said:

That is my plan at this point as well. We carry two spare sediment filters and one spare carbon filter. Removing the filters or re-routing the plumbing is a short process.

But building in a bypass sounds like a good winter project.

Click to expand...

A two-way/three port NPT tapped valve sure makes it a LOT easier, way fewer fittings. You may not find that valve at the box stores, but Defender has them.

I'll 2nd putting the filter on the pressure side of the pump, it's standard practice. A strainer is what's appropriate for the suction side to preclude starving the pump.

FWIW, I don't see any benefit in a .5 mic filter on potable water, unless you have some sensitive laboratory appliances on the system. Faucets don't care. Nor do I see a benefit in dual progressive filters. You'll never be able to see any difference. Use a single 10" T&O carbon filter downstream of the pump discharge. The T&O will keep the water tasting good and the icemaker ice palatable. We cruise full time, some areas really lay on the chlorine if they have lots of rain, it ends up making the tank water taste pretty bad, the T&O pulls it out.

Moved my pump, so it is in front of filter. It runs much quieter. Filter water before it goes into tank and also is filtered as used from tank. Water for flushing watermaker, filtered 2 more times.

HiDHo said:

This year I started filtering the water going into the tanks. This method is much easier than the whole boat filter I had been using and seems to be more effective. I haven't cleaned a faucet outlet airator of scale, etc since using the hose filter and we are living aboard using the tanks and boat water pump. I bought a two pack of these filters in the rv section at Walmart, but any rv retailer should have them. I added the inlet hose section for easy accessing the docks potable water faucets.

Click to expand...

I think you have the right idea. If you feel the need to filter the water on your boat, filtering before you put it in the tanks is the best plan. It's the simplest as well.

Had several point of use filters under sinks. Decided to get a large whole house filter housing and a carbon block filter. The filter and the housing were about $110. The replacement filter is about $65, rated for 20,000 gallons, and plan to replace it annually. Whole boat has nice water with no chlorine taste. Some municipal marinas seem to have a lot more chlorine taste in the water than others.



Ted

I only filter the galley and with a charcoal filter as well as a junk filter. Common household items, no idea what the micron rating is.
there is also a screen filter between the tank and the pump to catch large particles. that seems to plug from time to time with what is probably sediment from the water and tank.

IMO filter should not be on the input side of pumps because there is little suction with most pumps.