SailNet Community banner
  • SailNet is a forum community dedicated to Sailing enthusiasts. Come join the discussion about sailing, modifications, classifieds, troubleshooting, repairs, reviews, maintenance, and more!

Water filtration

3K views 31 replies 10 participants last post by  smackdaddy 
#1 ·
I bought a West Marine 3 LPM pump and downstream I used a standard 10" housing with a 5 micron filter. This lasted about 2 days. Pump ran but no water. Yes water in the tank, line primed. No trash in line just no output. I thought faulty pump. So I got another West Marine under warranty. Same problem but only after one day. No output even when I disconnect the filter. What am I doing wrong here? Do you guys even use a filter? What type?

Thanks in advance.
 
#2 ·
Most obvious question.. plumbed in in the right direction? Probably because it did work to start..

No other hidden/plugged filter in the system? Is there an inspection port/can you remove the actual pickup tube? Sometimes you'll get a pinhole in the pickup tube and it will suck air once the tank level falls below that point.
 
#3 ·
Yup, I use a 0.35 micron carbon block filter. The filter isn't the problem, unless you plugged the filter with dirty water, though 5 micron is not that fine.
 
#6 ·
I wonder how many bugs got in the tank. One way or the other, it was not supervised (cover, fill, vent). All openings should be guarded.
 
#5 ·
btw we use a faucet-mounted Brita filter that can be switched in and out. We only filter water we intend to drink, and don't filter dishwater etc so the filters last longer.
 
#7 · (Edited)
I tried every configuration, before the Max4 pump, after the pump, but could not get a satisfactory water flow with the 10" filter in the water line. Finally just removed it and did like Faster did, but with a Pur water filter on the spigot. Nary a problem since.
One would think an inline filter would be a necessity on our water systems but this seems to be another don't fix it if it ain't broke situation.
 
#8 ·
The intake inside the tank might be getting clogged. There may be chunky stuff in the tank. Try blowing back the intake line. If it works for a while and gets plugged up again, that has to be the problem. Cleaning out water tanks has to be done periodically.
 
#9 ·
Actually, if you cannot get flow with a 40 psi pressure system, something is broken and you just have not found it.

The fine (0.5 micron) 10" filters should give you about 1 gpm at 30 psi (any more than that makes a mess filling a pot--few kitchen taps are faster), and the pleated filters should get you up to 2 gpm, depending on the plumbing. I did a lot of testing on this last year.

Yes, this is less than the open flow rate, but I assume you have a pressure tank to buffer this. If no pressure tank, that could be part of the problem (these are PD pumps).
 
#10 ·
All these pumps need a good supply of water available at the inlet side. air ingress, blockage,crinks vents ??? The sound of the pump will tell you if the problem is up or down stream from the pump The accumulator(can't be too big) is an added convenience but only affects cycle time.Long time (and age)on pressure will affect the condition of the rubber valves in most rotary reed valve pumps. and they fail to suck and hold pressure.
 
#11 ·
Capt, well said. A PD pump needs a low restriction feed and a clear path to an accumulator, so that it can run at full flow. Then you can draw off from the accumulator in any manner.
 
#12 ·
All I have is a mesh strainer before the pump to protect it. The real filter I have is at a separate cartridge filter facet at the galley sink (not the main facet).
 
#13 · (Edited)
Here's a possibility:

How HIGH above the tank water level is that pump mounted?
Such (wobble plate diaphragm) pumps can only develop about 4" of mercury suction (approx. 4 ft of 'lift' on the suction side of the pump). If that amount of suction developed by the pump is less than the amount of lift distance - NO FLOW.

Such pumps should be mounted as close as possible to the top level of the tank so that the pump will be able to 'suck' water into the diaphragm plate, and once the diaphragm plate and internal valves are 'wetted' the priming will be complete and the pump can then develop pressure on the pressure side; hence, FLOW. The (excess) use on the suction side hosing .... of hose barbs, small diameter hosing, an octopus of hose diameter 'reducers', filters on the inlet, excess hose connections and elbows etc. will make that suction requirement (flow restrictions) 'worse'.
Also, its not unreasonable in a boat water system that is rarely/infrequently used to develop a 'bacterial plug' in the 'suction line' to the pump providing an additional flow/suction restriction.

If this is the case and to rule out this effect, suggest temporarily mounting the pump ON/AT the tank mid level using a long clear hose on the 'suction side' and do some trials with the pump at several 'altitudes' higher than the tank to see how HIGH this pump can 'lift'. Look for the presence of water in the clear hosing as you raise/lower the pump in relation to the tank - starting from HIGH to LOW level 'towards' the tank.

:)
 
#15 ·
Smack, the Brita Filter does not take care of bacteria, at least from what I've read about them. Therefore, I guess you will have to rely on chlorination of your freshwater tank to take care of the bugs, then the Brita filter will remove the Chlorine with activated charcoal.

Gary :cool:
 
#16 ·
Well that's the great thing about having a filter for drinking water. You can maintain a chlorine level in the tanks, but not have to drink it! And where most drop the ball on this is that they add bleach to the tanks, but never test for it to be sure of the level even though there are lots of cheap test kits around.

Of course if you are a lucky owner of a boat with aluminum tanks you have a problem.
 
#17 ·
I agree. That's why I purchased a $12 test kit on Amazon. And, I also have a PH test kit for around the house because I'm on a deepwater well that is somewhat acidic and have to run my drinking water through an acid neutralizer. My house is 50 years old and has all copper pipe, therefore, if the PH is not correct the acid quickly eats pin holes in the water pipes and heat pipes of my hotwater baseboard heating system.

The freshwater tank on my Morgan 33 is a 75-gallon plastic tank that is situated beneath the vee berth. Unfortunately, it does not have a deck fill fitting and I must remove the mattress from the vee berth to access the fill port. It's a real PITA, but 75 gallons is a lot of water for a 33 footer. I hope to change the fill system this winter, but I'm not sure if it's possible with my current configuration.

All the best,

Gary :cool:
 
#20 · (Edited)
Smak, did the same on Thane. 1500 liters in four aluminium tanks.with surge baffles. messy job but worth it .The epoxy in the hair eventually grew out. Even the bottled water in the store has a shelf life. Taint so pure even if there's no lumps.Just looked at the vid. I was in much worse shape and included a layer of cloth thruout and covered all aluminium as I seem to remember there's a conection with Alzimers.
 
#24 ·
Quick question...how long would you say the chlorinated water from the dock tap maintains it "bio-stability" before needing additional treatment? In other words, if we're out cruising and start off with our 105 gallons, go through it in a week or whatever, then refill from another chlorinated source, then repeat...

Is additional treatment required since we're continually moving chlorinated water through it? Is this additional chlorination more suited to boats/water that sit for longer? Or is it also an issue for boats being used?
 
#26 ·
Quick question...how long would you say the chlorinated water from the dock tap maintains it "bio-stability" before needing additional treatment?
At lot will depend on how clean the tanks and lines are and the temperature (higher temps will deplete the chlorine faster).

I've measured an acceptable free chlorine in the water weeks after filling the tanks. So that water is safe to drink even though it starts to have a bad taste sometimes.

The best answer if not using a tank filling within a couple of days is to maintain a high chlorine level that you verify by testing and to have a cartridge type of filter for drinking water.
 
#25 ·
Smack, a lot of this will depend on how often you have to refill or add water to the tank. I've taken tap water and placed it in a plastic jug, and if not refrigerated, after about four days, you can often see algae beginning to grow on the inside surface of the jug. With water from my 500-foot deep well, the process can be as short as three days.

I checked a web site a couple years ago about the amount of chlorine/chlorox required to sterilize tap water. The formula was 8 to 16 drops of 34-percent chlorine per gallon of water. That may seem like a lot of chlorox, but in reality, you can barely smell 8 drops in a gallon of water.

If my boat sits unattended for a couple weeks, I usually add a full cup of Chlorox to my 75 gallon tank - just to be on the safe side. Now, I don't drink it - I use it for showers, washing dishes, etc. For drinking I use bottled water and I keep that refrigerated. A case of bottled water really goes a long way. The pilgrims used beer instead of water, mainly because it was safer than water and never went bad. Pretty smart, those pilgrams.

All the best,

Gary :cool:
 
#27 · (Edited)
What happens if we add a U/V filter to this mix, without using any bleach in the water to preserve it?
Would placing the U/V filter on the end of the water maker system to feed clean water into a cleaned (cleaned w/bleach, then rinsed) tank, mean there was nothing in the water or tank to grow and spoil the water?
Or would it be best to use the U/V filter between the tank and the pump, cleaning any organisms out in that stage?
If we are running a watermaker, we must have bleach free water to rinse the membranes with, therefore I am really trying to stay away from bleach as I don't wish to damage the watermaker membranes in the flush cycle.
It has been suggested that some water filters will remove bleach from the water (dedicated line to rinse the membranes only), but actually determining whether one will actually remove the bleach (not just the taste) seems difficult.
It's not like those of us with watermakers can use 6 to 10 gallons of bottled water to rinse the membranes each time, even if we had a way to introduce it.
 
#28 ·
What happens if we add a U/V filter to this mix, without using any bleach in the water to preserve it?
Would placing the U/V filter on the end of the water maker system to feed clean water into a cleaned (cleaned w/bleach, then rinsed) tank, mean there was nothing in the water or tank to grow and spoil the water?
Or would it be best to use the U/V filter between the tank and the pump, cleaning any organisms out in that stage?
I am really trying to stay away from bleach as I don't wish to damage the watermaker membranes in the flush cycle. It has been suggested that some water filters will remove bleach from the water, but actually determining whether one will remove the bleach (not just the taste) seems difficult.
UV really needs to be placed in a high velocity (7-9 ft/second) continuous recirculation system to do any effective stun/kill. Yeah you may affect some 'kill' with UV but there are more effective, less energy consuming, and least costly ways .... 'clorox'.

With the massive amount of bacteria, etc. blowing about in the ambient atmosphere and in feed water there is no hard fast rules for the rapidity of reinfection. Hell, even parenteral drugs used for IV and direct injection have a 'shelf life' due to the statistical 'voracity' of bacteria and other organism growth even in 'sterile' solutions.

Of course bleach is a 'killer' to polyamide RO membranes. Consider to use some temporary 5 gallon soft-sided / collapsable containers, etc. for RO water that is chlorine free ... and then add your pickling or regeneration/recovery chemicals to that chlorine free water before rerouting it back to your RO.
 
#32 · (Edited)
Maybe we just need to sail to Norway...

"If the water is covered and of good quality to start with, in principle it can last a thousand years," he says.
Can water spoil? | ScienceNordic

True story here:

When I was in college, a buddy and me planned a 7-day trip to the Gila Wilderness in southern New Mexico. And it's a true wilderness area...



We bought topo maps, etc. and planned our route from a particular ranger station to the canyon. The map showed "intermittent streams", and I'd done lots of camping in New Mexico and Colorado before where that meant plentiful water sources and figured this would be similar. Then there was the Gila River at the bottom of the canyon (our destination) which was big and beautiful and wet and full of trout. We had water purification tabs ready to go. Solid, right?



Boy were we wrong. First, the Gila is at the upper end of the Sonora Desert. So to get to that wonderful canyon and river, you have to hike several miles of this stuff:



And in July, that kind of stuff is deadly. There is ZERO water.

We headed off very early in the morning, and went through the water we'd packed in in the first couple of hours. Then a few hours later as the temps were soaring we were starting to get all hallucinaty.

By the grace of God, we happened across a small stand of water with several cattle standing in it doing their business. It looked something like this (and I'm not exaggerating):



We scared the cattle out of the pond, built a small fire and started boiling the seriously nasty, brown water. After a couple of minutes boiling we then cooled it and strained it through a bandana, we then repeated this process a couple more times until the water was relatively clear.

We then dumped in water purification tabs and koolaid powder - then drank it up. It was AWESOME! And it saved our lives.

From that day forward, I've been pretty confident that public water is probably pretty okay...much better than we typically give it credit for. And DEFINITELY much better than what I had that day.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top