Watermaker preventive maintenance

[Shoalwaters]

I run my watermaker for 10 minutes every week or so using the watermaker's own fresh water flush system. In theory this keeps the membrane healthy and the pumps and valves exercised. Each time I do this there is a distinct smell of hydrogen sulphide (rotten eggs) from the water produced, so there is some bacterial growth going on in there.

The alternative approach is to "pickle" the system which involves dissolving 3 oz of sodium metabisulphite in 3 gallons of chlorine-free water, circulating it through the watermaker's system, draining it all out and plugging the membrane.

My system does not lend itself to being disconnected and reconnected like this, and it is asking for leaks in the high pressure connections. I also like to run the pumps and move the valves because "machinery left to lie down gets set in its ways".

I am wondering if there is a compromise: run the watermaker (say) every month using fresh sodium metabisulphite solution and leave it in there. This would prevent micro organisms from growing and give the metal bits a workout. The question is: would this do any harm to the membrane, pumps, valves and hoses?

Sodium metabisulphite is readily available and costs about 25¢/lb

 

[Larry M]

I run my watermaker for 10 minutes every week or so using the watermaker's own fresh water flush system. In theory this keeps the membrane healthy and the pumps and valves exercised. Each time I do this there is a distinct smell of hydrogen sulphide (rotten eggs) from the water produced, so there is some bacterial growth going on in there.

The alternative approach is to "pickle" the system which involves dissolving 3 oz of sodium metabisulphite in 3 gallons of chlorine-free water, circulating it through the watermaker's system, draining it all out and plugging the membrane.

My system does not lend itself to being disconnected and reconnected like this, and it is asking for leaks in the high pressure connections. I also like to run the pumps and move the valves because "machinery left to lie down gets set in its ways".

I am wondering if there is a compromise: run the watermaker (say) every month using fresh sodium metabisulphite solution and leave it in there. This would prevent micro organisms from growing and give the metal bits a workout. The question is: would this do any harm to the membrane, pumps, valves and hoses?

Sodium metabisulphite is readily available and costs about 25¢/lb

Mike: When we pickle ours we run the solution then shut it off (twice in 5 years). We don't drain the system. You should be able to pickle the system for 6 months to a year and not worry about it. What's the manufacturer say? What's your TDS been running?

 

[Shoalwaters]

Larry, my watermaker is a set of off-the-shelf components by Quality Water Works. The manual says drain after pumping the solution through "....you want a wet environment inside the membrane, not flooded". From your experience it sounds as though I can leave the juice in there without doing any harm. I don't have a TDS meter. When the sytem has been running for about some time, I smell and then taste the output. If I can detect any trace of saltiness (or anything else) I let it run a little longer. The output - 10gph at 800 psi - is as good or better than the mfg says I should get.

 

[Tidahapah]

Guys,
Similar to Larry I don't often pickle mine probably only 2 or 3 times in the last 5 years. When I do I leave it floooded and then flush it thru for a good 25/20 mins on start up.
Other wise I just flush it with pure home made water and let it sit.
My water maker did not come with a TDS meter but I picked up a small remote duel reading (for 2 membranes) unit for about $60.00.
Well worth the money.
http://www.tdsmeter.com/products/dm2ec.html
This is a very similar unit to mine.

Benn

 

[Larry M]

I run my watermaker for 10 minutes every week or so using the watermaker's own fresh water flush system. In theory this keeps the membrane healthy and the pumps and valves exercised. Each time I do this there is a distinct smell of hydrogen sulphide (rotten eggs) from the water produced, so there is some bacterial growth going on in there...

Mike: I bet the smell is coming from your pre-filters. When we rinse our system, it's 2 step: membrane and then the pre-filters. Trying to get all the salt water out of the pre-filters short of removing them is difficult. We get the smell also but have learned to live with it.

 

[Shoalwaters]

Thanks Larry and Benn; that's just what I needed to know. Damn that little meter is tempting.

 

[Tidahapah]

As Larry has stated , the prefilters are your biggest source of smell.
If I am leaving mine for any length of time , after flushing or pickling I then remove the prefilters and leave the filter boxes dry.
The filters are throw away and one must remember tht salt water is a living organisim so when it is left stagnent it will die and start to smell and contaminate the elements anyway.
Cheers
Benn

 

[Shoalwaters]

Your point is well made Benn. I've been doing some reading on sodium metabisulphite, and apparently it smells of rotten eggs too. Sometimes you just can't win!

 

[SV THIRD DAY]

Hey Mike...Please get a TDS Meter because you can't start tasting the "salt" until it reaches a level that will be hard on your Kidneys. So the only way to know if your RO water is safe to drink (Below 500ppm TDS) is by using a TDS meter. I was cruising with a couple in the Sea of Cortez that were going by taste and they started to think something was wrong with their water maker when their cat wouldn't drink the water and their herbs started to die in the Pots!

Rich
SV THIRD DAY

 

[Larry M]

Rich: Welcome.

Edit: I hope I don't get in trouble for this but Lena & I first met Rich in the Sea of Cortez in 2009. He's a good source for RO information. He's also the founder and co-owner of Cruise RO Water and Power.

Cruise RO Water and Power

 

[Shoalwaters]

Hey Mike...Please get a TDS Meter because you can't start tasting the "salt" until it reaches a level that will be hard on your Kidneys. So the only way to know if your RO water is safe to drink (Below 500ppm TDS) is by using a TDS meter. I was cruising with a couple in the Sea of Cortez that were going by taste and they started to think something was wrong with their water maker when their cat wouldn't drink the water and their herbs started to die in the Pots!

Rich
SV THIRD DAY

Thanks for the heads-up Rich; I will research the available meters.