Adding Bleach to RO Water

[merrydolphin]

What do is have a small tank dedicated to rinse and when I am done making water I run the watermaker product water into that tank with a diverted valve. Then devert the input water from sea to rinse tank ( a 5 gal Jerry jug). RO water is the best fresh water flush water. I do this very often and if I am going to leave the water maker sit for more than a couple days or so, I flush it. Nothing better for them than to fresh water flush them. I have had excellent services this way. And never have to worrry about not having quality flush water. I never 100% trusted my membrane to a charcoal filter. I’m sure they are fine as long as you really keep up with it. But RO water is the best.
I have owned both Spectra 8.5 gph and a 110V 20 gph system, ( two different boats). The 110V system I usually just ran once every week and a half or so. Sometimes as long as 2 weeks. . Would run it for 10 hrs Straight to fill my tank and jugs. The Spectra I used about every other day to every day.

[Mainstreet]

I found that adding a litre of hydrogen peroxide to 100 gallons of RO water resolved any issues with bacteria, taste or odour.

[Pillroller]

100 % Alcohol as potable spirit drink. NO CHANCE. It is extremely expensive to make 99% alcohol Or even 95% I know I used to buy it for my hospital Pharmacy. It may have been 100 degrees "proof spirit" which would be approx. 50% V/V. By distillation the max strength is c60/70 %. after that you have to work harder. You can buy 190proof "Grain Spirit @ 50£ sterling for 750ml. Pretty expensive? R.

[dougweibel]

Let's drift this thread in a different direction.

My water maker has an automated weekly fresh-water flush. I have been using this feature rather than pickling the water maker when off the boat for 2 to 4 months (and would probably try it for longer if needed). This requires the water tank to be refilled along the way, as it would otherwise be depleted by the flushes, so I use a setup with 2 10" carbon filters in series to fill the tank with city water, and the water maker FWF has a separate 5" carbon filter. Seems to be working out fine. I'm curious what others think of this - not the potential for chlorine in the flush water, but the idea of weekly flushing versus pickling for 4 months (or indefinitely).

[Rainbow48]

Better ask the manufacturer of the RO unit before running bleach through the system. Many advise that the chlorine in the bleach will destroy the RO membrane over time.

[sailorboy1]

Originally Posted by dougweibel

Let's drift this thread in a different direction.

My water maker has an automated weekly fresh-water flush. I have been using this feature rather than pickling the water maker when off the boat for 2 to 4 months (and would probably try it for longer if needed). This requires the water tank to be refilled along the way, as it would otherwise be depleted by the flushes, so I use a setup with 2 10" carbon filters in series to fill the tank with city water, and the water maker FWF has a separate 5" carbon filter. Seems to be working out fine. I'm curious what others think of this - not the potential for chlorine in the flush water, but the idea of weekly flushing versus pickling for 4 months (or indefinitely).

My thread drift answer is I feel that is fine. I would change out the prefilter also if that were my plan as it is nothing but a source of nasty water.

[rapanui 2]

Originally Posted by brendanwalls

When I bought my boat 5 years ago I was advised to put alcohol in the water tanks to prevent freezing, and so I put a litre of Polish Spirit 100% alcohol in my 12 gallon water tank, which I only use for cleaning purposes. It always smells good even after 5 years of using and topping up, so I assume no algae.

I advise you to put a little of water in puncheon trinidad rum(75% proof) before you drink ....

[IanTrail]

We have been living on board with a watermaker for more than 10 years. I've never wanted to put chlorine in the tanks because of the problem of flushing the watermaker. Membranes are very expensive! OK - the carbon filter should take it out but how do you know when to replace the filters? So generally we don't drink tank water unboiled - tea, coffee and cooking is OK but for drinking we stick to bottled water. We also fill-up with shore-side water when convenient so I rely on the carbon filter to take out that chlorine when flushing.

Here's an idea that's been on my 'Improvements' list for few years but never made it to the top yet. I need about 10 litres of pure water to flush my watermaker for the manufacturer's recommended 90 seconds. So I thought, what if I put a 10 litre header tank between the watermaker output and the water tank input and drew the watermaker flushing water from the header tank rather than the main tank. Then I could add chlorine to the main tank and I'd always have 10 litres of pure water ready to flush the watermaker. Maybe one day I'll get around to doing it.

To round off:
We were ashore one day I remembered that I ought to flush the watermaker. So I took out my iPhone and said "Hey Siri, remind me to flush the watermaker". When I got back to the boat I had a new reminder: "Remember to flush the wall Jamaica". Nice try!

[noelex 77]

Originally Posted by Rainbow48

Better ask the manufacturer of the RO unit before running bleach through the system. Many advise that the chlorine in the bleach will destroy the RO membrane over time.

Chlorine will damage or even destroy the membrane. An installed carbon filter removes the chlorine and protects the membrane, but only providing it functions correctly. This depends on the carbon filter seating correctly (no leaks or bypass) and regular, scheduled replacement of the filter.

If the membrane is damaged from chlorine, then replacement is reasonably expensive and involved. However, the biggest issue is sourcing a replacement in remote locations. As they deteriorate in storage, it is not practical to carry a replacement as a spare part. For a long distance cruising boat this can be an issue.

A belt and braces approach is my preferred option and this is why I installed a system where the watermaker is only rinsed with product water. This eliminates the chance of damage. It requires a more specialised installation, but if designing the system from scratch this protection system is worth considering.

[Lepke]

I make all the fresh water used on the boat. I winter in fresh, but my private dock doesn't have city water. I chlorinate my tanks because in time they will become contaminated. Maybe by air drawn in thru the vents? Galley sink has filters. When I make water, I have a clean 5gl bucket with a couple added fittings and it gets the last ro water. That water then goes thru the whole system, including the low pressure pump. I don't pickle, but a couple times a year do a membrane cleaning, usually in the winter because I let the watermaker sit too long. Membranes are about 10 years old.

[aldenfootcare]

I have used bleach, CLOREX, this past summer in my water tank, ( 50 gallon) 2 capfuls of Chlorine .Within a month, my screens are plugged for my sink faucet.I find a clear crystal like substance that builds up and clogs it up. Does anyone else have this problem?

[nofacey]

Early suggestion to use pool chlorine test strips is a great one.

Thread drift question about automated FW flushes while gone for months = asking for a failure. That’s a clear” pickle and walk away” response.

While we lived aboard 6yr cruising, generally ran watermaker every 5-7 days. Turning over the Fw tanks that frequently negated need to chlorinate.

[AKA-None]

Don’t we have at least one person on cf that makes or sells water makers?

[brendanwalls]

Originally Posted by Pillroller

100 % Alcohol as potable spirit drink. NO CHANCE. It is extremely expensive to make 99% alcohol Or even 95% I know I used to buy it for my hospital Pharmacy. It may have been 100 degrees "proof spirit" which would be approx. 50% V/V. By distillation the max strength is c60/70 %. after that you have to work harder. You can buy 190proof "Grain Spirit @ 50£ sterling for 750ml. Pretty expensive? R.

https://www.laballey.com/products/bu...d-1-pint-29-90

[sailorboy1]

I am so impressed with the thread drift here that people will research. It is amazing.