Water Filtration Question

[GalaxyGirl]

Hello guys,

Yesterday it occurred to me that it is going to be a real pain in the booty having to constantly lug and store gallons and gallons of drinking water for 7-11 people.

I was thinking I might be better off installing a water filter for our drinking water under the galley sink. Has anyone done this? Did you use a Home Depot model or a marine grade? Are you happy with it? Anything that I should consider?

[thinwater]

Pre-filter the water when you fill. Many options, including a $12 filter from Walmart.
Camco TastePURE RV and Marine Water Filter: ATV, Motorcycle, & RV Accessories : Walmart.com

Pentek DVG-50. This will meet NSF P231 for a microbioogical purifier. $109
Pentek DVG-50 Filter Cartridge for VGS-600, VCT-1 Only $108.99

Save $90 and use this cartridge in the US. Still NSF 53. $15
http://www.filtersfast.com/P-Pentek-FloPlus-10-Carbon-Block-Water-Filter.asp
...either of which fit in this housing...

10" 3G housing. $12
Pentek 158620 1/2" 3G Slim Line 10" Blue Housing Only $11.99

This will get you better quality water than you have at your home tap. The system described is really single-tap; it can handle multiple taps, but not a shower. You should not need this for the shower if good tap water is available and the tank is properly maintained (pre-filter and clean/sanitize annually). The $27 system should be all you need.

-----

Home Depot is over priced for this stuff and does not have the same selection. Pentek makes products and then private labels for GE etc.

There are more expensive systems that are not NSF certified. There are more expensive systems based on proprietary cartrige systems. This is based on universal products--parts and replacements should be available most anywhere.

[ranger58sb]

Our marina's on a well. We filter when we fill the onboard tanks, with household-sized stuff: first through a Pentek Big Blue housing with DGD-2501 dual-gradient 25/1 micron filter element... then into a smaller GE S,artwater housing with a Pentek CBC-10 .5 micron carbon filter. The latter affects flow rate.

Then we almost always use water from onboard tanks, so it cycles often; we seldom use the shorewater connection (partly because without extra routing, it creates a trip hazard at our home dock). When we DO use the dockwater connection, we only use the Blig Blue.

Everything travels with us, although I could also install a set of filters at our home dock and just leave it there when we move.

We also then use a Pur filter pitcher for drinking water. Brita would be similar, but this particular pitcher fits nicely in one of our fridges. I could have thought about installing separate drinking water filters on each sink, but the "fancy" faucets (wands, spray options, etc.) make that difficult.

filtersfast.com

There are several threads about flushing/preparing freshwater tanks... so all the filtration can be effective. Search for info by Peggie Hall.

-Chris

[Cotemar]

Filtering water works well if your using the system all the time (daily).

If you’re just using your boat on weekends, BE CAREFUL. Filtered stagnant water will make you very sick.

Why, because the water in the filter under the sinks is cooking from the heat of the boat all week and making nasty bugs in the filter. Then you drink it all weekend long.

Ask me how I know this.........

[GalaxyGirl]

Originally Posted by Cotemar

Filtering water works well if your using the system all the time (daily).

If you’re just using your boat on weekends, BE CAREFUL. Filtered stagnant water will make you very sick.

Why, because the water in the filter under the sinks is cooking from the heat of the boat all week and making nasty bugs in the filter. Then you drink it all weekend long.

Ask me how I know this.........

That sounds horrifying

[GalaxyGirl]

Originally Posted by thinwater

Pre-filter the water when you fill. Many options, including a $12 filter from Walmart.
Camco TastePURE RV and Marine Water Filter: ATV, Motorcycle, & RV Accessories : Walmart.com

Pentek DVG-50. This will meet NSF P231 for a microbioogical purifier. $109
Pentek DVG-50 Filter Cartridge for VGS-600, VCT-1 Only $108.99

Save $90 and use this cartridge in the US. Still NSF 53. $15
http://www.filtersfast.com/P-Pentek-FloPlus-10-Carbon-Block-Water-Filter.asp
...either of which fit in this housing...

10" 3G housing. $12
Pentek 158620 1/2" 3G Slim Line 10" Blue Housing Only $11.99

This will get you better quality water than you have at your home tap. The system described is really single-tap; it can handle multiple taps, but not a shower. You should not need this for the shower if good tap water is available and the tank is properly maintained (pre-filter and clean/sanitize annually). The $27 system should be all you need.

-----

Home Depot is over priced for this stuff and does not have the same selection. Pentek makes products and then private labels for GE etc.

There are more expensive systems that are not NSF certified. There are more expensive systems based on proprietary cartrige systems. This is based on universal products--parts and replacements should be available most anywhere.

Hmmmm, I wasn't even considering the water from the hose, maybe I should be. I'm concerned that the boat is almost 30 years old. Figuring there must be contamination in the water lines. Can't see drinking water that runs through the lines. I don't care about showering, etc, but drinking is a different horse. I was thinking to filter under the kitchen sink so that the clean water doesn't get re-contaminated running through the boat?

[thinwater]

Ranger 42C: Defiantly agree the CBC-10 is another great choice. I have used that one. Though not NSF certified, it would probably pass (Pentek cerified the one I listed, which is VERY similar--often mnf don't certify every filter due to cost). 0.5 micron rated carbon block will get cysts and the vast majority of bacteria and viruses.

Cotemar. We are not suggesting removing chlorine; even the hose filter I quoted only removes about 25% of the chlorine (even NSF rated "chlorine" filters are not required to remove more than 25% in the lowest category). I tested this one for chlorine removal. It is also up to the user to re-chlorinate as needed (1-4 ppm). This should be obvious. Additionally, the filter should be a bateriostatic sort; in this case I suggested one containing KDF media (copper/zinc), which has this property. We have also specified specifically anti-microbial filtration down-stream.

Galaxygirl. Ranger and I are BOTH describing under-sink filtration. You are right, it needs done relatively close to the tap. However, it does not need to be literally under the tap; boats are not the big and you should sanitize the lines with bleach at least annually, as part of the tank sanitation process. The fine filters must be between the tank and the tap, on the pressure side of the pump. The fine filters will slow the flow to <1 gpm, so they are not for the shower. Due to space, my final filtration is in a locker about 6 feet from the tap--easier to service there and the under-sink space is premium.

--

As a general rule do NOT use plain (granulated carbon) for intermittent marine applications; as Cotemar stated, it really likes to grow bacteria and could make things worse. Do not use sediment filters with cellulose elements; they will grow stuff and rot.

I was very specific for good reasons. The rated elements (NSF 53 and P231) have been tested with microorganisms and are intended for this sort of application; their primary market is untreated, non-chlorinated well water with possible failed septic waste. They are very good filters.

Also consider adding a screen to the tank vent if it isn't there. It is in the plumbing code, but many manufactures skip it. Bugs crawl into tanks, even mosquitoes.

[ranger58sb]

Originally Posted by GalaxyGirl

Hmmmm, I wasn't even considering the water from the hose, maybe I should be. I'm concerned that the boat is almost 30 years old. Figuring there must be contamination in the water lines. Can't see drinking water that runs through the lines. I don't care about showering, etc, but drinking is a different horse. I was thinking to filter under the kitchen sink so that the clean water doesn't get re-contaminated running through the boat?

Originally Posted by ranger42c

There are several threads about flushing/preparing freshwater tanks... so all the filtration can be effective. Search for info by Peggie Hall.

Flushing and so forth includes hoses and onboard lines. Once you're satisfied the system is properly cleaned out, constant use will usually keep it that way.

-Chris

[GalaxyGirl]

Originally Posted by thinwater

Ranger 42C: Defiantly agree the CBC-10 is another great choice. I have used that one. Though not NSF certified, it would probably pass (Pentek cerified the one I listed, which is VERY similar--often mnf don't certify every filter due to cost). 0.5 micron rated carbon block will get cysts and the vast majority of bacteria and viruses.

Cotemar. We are not suggesting removing chlorine; even the hose filter I quoted only removes about 25% of the chlorine (even NSF rated "chlorine" filters are not required to remove more than 25% in the lowest category). I tested this one for chlorine removal. It is also up to the user to re-chlorinate as needed (1-4 ppm). This should be obvious. Additionally, the filter should be a bateriostatic sort; in this case I suggested one containing KDF media (copper/zinc), which has this property. We have also specified specifically anti-microbial filtration down-stream.

Galaxygirl. Ranger and I are BOTH describing under-sink filtration. You are right, it needs done relatively close to the tap. However, it does not need to be literally under the tap; boats are not the big and you should sanitize the lines with bleach at least annually, as part of the tank sanitation process. The fine filters must be between the tank and the tap, on the pressure side of the pump. The fine filters will slow the flow to <1 gpm, so they are not for the shower. Due to space, my final filtration is in a locker about 6 feet from the tap--easier to service there and the under-sink space is premium.

--

As a general rule do NOT use plain (granulated carbon) for intermittent marine applications; as Cotemar stated, it really likes to grow bacteria and could make things worse. Do not use sediment filters with cellulose elements; they will grow stuff and rot.

I was very specific for good reasons. The rated elements (NSF 53 and P231) have been tested with microorganisms and are intended for this sort of application; their primary market is untreated, non-chlorinated well water with possible failed septic waste. They are very good filters.

Also consider adding a screen to the tank vent if it isn't there. It is in the plumbing code, but many manufactures skip it. Bugs crawl into tanks, even mosquitoes.

This is great info and I really want and need to understand.

Where would I find the tank vent? I didn't realize there was one.
I'm confused about the filters. The blue one is for the under the sink? Does the $100 membrane go inside of that? Does West marine carry this stuff in the store or would I have to order online?

Thanks for your help.

[thinwater]

Originally Posted by GalaxyGirl

This is great info and I really want and need to understand.

Where would I find the tank vent? I didn't realize there was one.
I'm confused about the filters. The blue one is for the under the sink? Does the $100 membrane go inside of that? Does West marine carry this stuff in the store or would I have to order online?

Thanks for your help.

Can't say about the vent location. It should be on the top of the tank, and it could go anywhere (fuel and holding tank vents go to through-hulls, but freshwater tanks often terminate in the cabin).

I did this a while ago, but just posted it:
Sail Delmarva: Freshwater Tank -- Are Bugs Swimming the Back Stroke in There?

Yes, the cartridges go in the housing. The 3G housing takes either style filter. While Home Depot does carry universal housings, they do not carry 3G, which is needed if you ever go for the high-spec filters--and the 3G housing is the same price as the universal. It is also backwards compatible (fits all standard 10" cartridges).

No, Home Depot doesn't carry any of the good filters. It is CRITICALLY important to have the right cartridge, as they serve VERY different purposes; A typical pleated or granulated carbon filter will NOT stop microbes. Filtersfast.com is very good, and much cheaper too.

This is a 5" slimline housing, but you will get better flow with the 10" housing I quoted above. I may switch next time, as I have room for the longer bowl (all I have to switch is the bowl, the beauty of universal housings).


To sumarize, and maybe to clarify some of what I said, clean water has 4 steps:
1. Clean and sanitize the tank.
2. Pre-filter at the hose-end. The hose is probably the greatest risk. The purpose here is just to keep sludge out of the tank.
3. Maintain the tank. Maybe add bleach (a few ppm--get aquarium test tapes if you want to be right). Screen the vent.
4. Filter just before the tap. That's where we talk about 3G housings and sub-micron filters (the NSF P231 filter is rated at 0.019 microns--that's small!). Here is where you fix taste and stop any bugs the chlorine missed. Should taste like, and be as safe as, bottled water when you are done.

This is the very short version, the results of both field and cost research. I know versions that work well and cost 4-40 times more! I'm currently working on 3 articles for Practical Sailor on the topic, and this sort of dialog helps me to understand the questions better. So thank you!

[J Clark H356]

Look at SafeH2O Model 512. This is a full boat system for $285. It has a 2 micron, then a 10 micron and then goes through a UV lamp. I put one on last year just after my water pump and before my distribution manifold. We took a cruise to Florida last winter from Kentucky Lake and we used water from many sources. We drink, shower, brush teeth, cook and never had to worry a minute with this system. I highly recommend it and it is good to a flow rate of 3GPM. My water pump is 2.8 GPM, so it works great. Google SafeH20 and it will take you to their website. Annual maintenance is $53 worth of parts including changing out the UV light and all filters.

This is a total solution for multiple and questionable water sources.

[thinwater]

^^ SafeH2O Model 512

Good tech... but not NSF/ANSI certified. I think you will find only a dozen units are NSF/WQA certified as microbiological purifiers, though hundreds make the claim. More expensive, more maintenance, more power, more complexity, and more bulk. I don't think this is the direction technology is moving, not for sailors, IMHO. True, it delivers more volume, but I doubt that matters to most. I can see that for a large boat traveling through the 3rd world, such makes sense. However, I would argue that in US waters you would have had exactly the same security from a $26 NSF 53 certified combination with a $15 maintenance cost.

------

The other thing we all need to remember, which WHO regularly points out, that unless you live in a plastic bubble, the "9s" only matter if that is your sole source of exposure. Add raw veggies, swimming, eating out, shaking hands, fountain sodas, bottled water, and fresh air, and at MOST 80% of your exposure to water-borne illness is the drinking water from the boat. They argue that anything past 99% effectiveness is probably fluff in real life, and the details of compliance are far more important. At that point, there is the rest of your life to consider. Additionally, the vast majority of sailors and people don't filter at all in the US and do just fine--without even considering untreated well water and rainwater--so anecdotes tell us little; we wouldn't have gotten sick anyway. This is why certification matters; it represents and independent measure.

[ranger58sb]

Originally Posted by thinwater

Ranger 42C: Defiantly agree the CBC-10 is another great choice. I have used that one. Though not NSF certified, it would probably pass (Pentek cerified the one I listed, which is VERY similar--often mnf don't certify every filter due to cost). 0.5 micron rated carbon block will get cysts and the vast majority of bacteria and viruses.

Defiantly?



I actually think the CBC-10 would turn out to be a bit of overkill for most folks if used as we do, to fill our freshwater tanks. Especially if an in-line filter closer to the tap can be used to select drinking water. Using a .5 micron filter as we do for water that's also used for showering, dishwashing, etc. is a bit much.

It's easy enough for me to do, though, and costs me no appreciable extra effort (except for ordering a new filter element from time to time)... so that's our continuing regimen. And we use only the 2501 when hooked up at a marina with decent city water; otherwise, water pressure (already at only 35 psi, because limited by our incoming pressure regulator) caused by the CBC-10 would be even further reduced... not so great.

And thanks for the tip about the FloPlus-10, BTW. That sounds even better, for our purposes.

-Chris

[thinwater]

Originally Posted by ranger42c

Defiantly?

---I spell that one wrong ALL the time. But if holding my fist in the air helps!



I actually think the CBC-10 would turn out to be a bit of overkill for most folks if used as we do, to fill our freshwater tanks....

I'm sure I was unclear. As you state, carbon block filters are for point-of-use filtration. However, I can imagine situations where combining that with a 5-10 micron pre-filter might not be crazy (3rd world). It would be slow and get a bit expensive.

-Chris

See above.

[Stu Jackson]

Originally Posted by GalaxyGirl

Hmmmm, I wasn't even considering the water from the hose, maybe I should be. I'm concerned that the boat is almost 30 years old. Figuring there must be contamination in the water lines.

Maybe, IIRC, one of your earlier questions was about the heads on the boat. If so, then I must have recommended Peggie Hall's book:
Get Rid of Boat Odors

I also believe she included a section on Recommissioning Water Systems.

You're right, it's the hoses. My boat is 27 years old and I just spent a few days replacing all the plumbing lines. Not that hard a job, lots of easy-to-work-with 1/2" hose and clamps.

See reply #6, here: hot water "rotten egg" odor

The information on filtering given here is very good if you choose to go that route. But even if you do, it's a waste if you don't either recommission your system (and it's the hoses not the tanks that are usually an issue) or replace the hoses.

Your boat, your choice. Good luck.

PS - Have you bought the book yet?

PPS - And while we're on books, have you bought Nigel Calder's Boatowners Manual for Mechanical & Electrical Systems yet? These two books will save you oodles of time scratching your head.