Caring for Dock Water Filter

[Muaddib1116]

Interesting. So if I am in an area where I'm using my watermaker exclusively for long periods, and don't add chlorine, I risk getting growth in my tank?

[rslifkin]

Originally Posted by Muaddib1116

Interesting. So if I am in an area where I'm using my watermaker exclusively for long periods, and don't add chlorine, I risk getting growth in my tank?

Potentially, yes. If any hint of anything gets in through the tank vent or any other method, yes, things can grow in the tank if it's completely non-chlorinated. This is also why boats that don't get used much get scummy water systems more easily. When the water in the tank sits for a while, the chlorine level drops (some evaporates and is lost out the vent, some is used in killing stuff that tries to grow) and eventually you're left with a tank with no chlorine residual.

That issue is why city water carries a chlorine residual, rather than just being disinfected and then having the chlorine stripped back out. The residual is intended to keep stuff from growing in the pipes, etc. before the water reaches your house (and eventually your faucet).

[thinwater]

Originally Posted by Muaddib1116

The life of the filter? Wouldn't carbon being sacrificially oxidized make the chlorine removal life shorter? What are the implications of this?

No, the amount of carbon oxidized is very, very small (only 1-2 ppm Cl in the water). Additionally, the chlorine burns up some of the adsorbed organic material.

[doublewide]

Interesting thread. I think the following are true:

Chlorine is harmful to aluminum tanks.

Chlorine can be removed by carbon, but it takes long contact time. You don't want to take hours to fill your tanks, so an in-line carbon filter is not a practical choice.

On the other hand, Chlorine can be removed completely and quickly by adding vitamin C.

The reaction is:
C5H5O5CH2ONa + HOCL → C5H3O5CH2OH + NaCl + H2O

Sodium ascorbate + Hypochlorous acid → Dehydroascorbic acid + Sodium chloride + water

Vitamin C is readily available, and very cheap. It takes only 4 grams of ascorbic acid to dechlorinate a 100 gallon tank of city water containing 4 mg/liter of chlorine, typically the amount found in city water.

That invites the question: do you really want to completely dechlorinate your drinking water? Wouldn't you prefer to just adjust the chlorine to 1-2 mg/liter, safe for you and at the same time less damaging to your tanks?

I think I will start a thread on this subject, hoping to learn how best to have pure water while minimizing the damage to my tanks. Is there a water-chemist out there?

[rslifkin]

Chlorine does need contact time with carbon, but compared to most of the other stuff carbon can remove, chorine gets removed fairly quickly.

[Tellie]

Here's what we recommend. Forget the charcoal filter on your fill hose. The chorine found in good residential water helps keep the growth down in your freshwater tank/s. You should fill your tanks with this if you trust the source. All watermakers should have a carbon filter installed on the unit to take care of this residual chlorine. Also, adding nothing but RO water to your tanks is almost akin to fertilizing any growth in your tank, and there is ALWAYS growth in all tanks. What you don't want to do with a watermaker installed is to add chorine to the tanks as you will almost certainly add too much overpowering your watermakers carbon filter. The best advice is a good post freshwater tank filtration such as a SeaGull point of use filter. Though the watermaker will produce great water, dumping RO water into your freshwater tank/s is akin to putting really good Rum into a dirty glass.

[valhalla360]

Originally Posted by rslifkin

Potentially, yes. If any hint of anything gets in through the tank vent or any other method, yes, things can grow in the tank if it's completely non-chlorinated. This is also why boats that don't get used much get scummy water systems more easily. When the water in the tank sits for a while, the chlorine level drops (some evaporates and is lost out the vent, some is used in killing stuff that tries to grow) and eventually you're left with a tank with no chlorine residual.

Depends...
- If you start with a clean system and you are only introducing pure RO water, there is very little in the way of minerals and organics to feed a biological growth process. It's simply an uninviting place for microbes to grow.
- If you introduce mineral and organic contaminants, now it's a concern as the microbes may wind up with favorable growing conditions.

As indicated boats that get a lot of use have less of an issue as the excess of microbes tend to be flushed out before they can build up...and a little chlorine from the city water tends to kill them off.

[rslifkin]

Originally Posted by valhalla360

Depends...
- If you start with a clean system and you are only introducing pure RO water, there is very little in the way of minerals and organics to feed a biological growth process. It's simply an uninviting place for microbes to grow.
- If you introduce mineral and organic contaminants, now it's a concern as the microbes may wind up with favorable growing conditions.

As indicated boats that get a lot of use have less of an issue as the excess of microbes tend to be flushed out before they can build up...and a little chlorine from the city water tends to kill them off.

Yes, there's not all that much growth potential. Which is why pretty much any detectable chlorine residual is enough to keep things from growing (it doesn't have to be much, even 0.2 ppm of chlorine is plenty in the tank). But tiny specks of dust and bacteria and such can get in through the tank vent over time, so even if it starts perfectly clean and you only ever put clean, filtered, sterile water in the tank, there's no guarantee it'll stay clean.

[thinwater]

Originally Posted by rslifkin

Yes, there's not all that much growth potential. Which is why pretty much any detectable chlorine residual is enough to keep things from growing (it doesn't have to be much, even 0.2 ppm of chlorine is plenty in the tank). But tiny specks of dust and bacteria and such can get in through the tank vent over time, so even if it starts perfectly clean and you only ever put clean, filtered, sterile water in the tank, there's no guarantee it'll stay clean.

This is why potable water tank vents should have screens, at least fine enough to keep bugs out (yes, they do climb in there and die). It is in the land building code for water tanks.

[rslifkin]

Originally Posted by thinwater

This is why potable water tank vents should have screens, at least fine enough to keep bugs out (yes, they do climb in there and die). It is in the land building code for water tanks.

Absolutely agreed on the screens. But I figure no screen is realistically going to be fine enough to keep airborne dust out (otherwise it would clog very easily).

[Martinini]

Or look into Hydrogen Peroxide instead of chlorine.

[stw]

Great thread, thank you.

I had the same question regarding storage of dockside sedment filters between usage.
Sample filters
5-micron NeoPure pleated polyester
1-micron Aquaboon pleated polypropylene

There may be different recommendations based on storage time between usage:
three-days ?
one-week ?
two-months ?
six or more months probably demands a new filter ?

I have read a few different recommendations. Are these the common best practices?
1) remove filter and dry within reason
2) store in sealed container

If a sealed container is desired, why not leave the filter in the housing and cap the openings? could be left wet or dry(ish)