Chlorine Levels

[teamplex65]

I am in the process of learning to understand and maintain the RO system better. Our distributor usually checks it for us when they stop by, but I want to begin checking ourselves weekly.

I have ordered a TDS kit, and a Chlorine/PH kit.

I received the chlorine kit today and did 3 tests. The kit requires you to fill a tube with water and drop 4 drops in it. It changes from clear to yellow. The darker the yellow, the more chlorine.

Tap water from city = no change
After RO tank = no change
In Spot free tank = no change

Is it possible that the city supplied water has no chlorine in it?

 

[mjwalsh]

I am in the process of learning to understand and maintain the RO system better. Our distributor usually checks it for us when they stop by, but I want to begin checking ourselves weekly.

I have ordered a TDS kit, and a Chlorine/PH kit.

I received the chlorine kit today and did 3 tests. The kit requires you to fill a tube with water and drop 4 drops in it. It changes from clear to yellow. The darker the yellow, the more chlorine.

Tap water from city = no change
After RO tank = no change
In Spot free tank = no change

Is it possible that the city supplied water has no chlorine in it?

teamplex65,

It was explained to me by our water department people here in Bismarck that chlorine dissipates when sitting in the pipes & tanks etc. This is why when the city employees when they field check the water they pick our laundromat sink abut once a week. Even then they run the water for awhile to make sure they are getting a more true reading. Let us know if that makes a difference. I use the cellulose acetate membrane for our RO so I have to worry about pH more than chlorine.

 

[MEP001]

The RO system will filter out chlorine (at least until the membranes are destroyed), so you won't find any in the tank. Chlorine will be concentrated in the RO reject water, so if you want to get a stronger, more noticeable reading, take it there. If that shows no indication then you're safe.

It's quite possible that there's not enough chlorine in the city water to indicate with the test kit.

 

[Ghetto Wash]

I don't understand the difference between:

"after RO tank" and "in spot free tank"

Isn't that the same place?

If you want to check your chlorine tester, just find some swimming pool water and check it. There should be chlorine in there.

 

[Whale of a Wash]

after the ro and in the tank is the same water. But chlorine if there is any will gas out if not covered. So the reading is only good as it is rejecting the water.
If you have strong chlorine in your water leaving a pitcher in the fridge overnight the chlorine will gas out.

 

[mac]

I broke down and bought an electronic chlorine tester. We service a lot of washes so the cost was justified, about $200 as I recall. I just never trusted those kits from the pool supply stores. It measures chlorine down to 1/100 of ppm. We usually see a reduction of about 100 fold between the sides of the charcoal tank.

 

[teamplex65]

Part of the over testing was because we had just received the kit and were testing it everywhere. I checked with our city and the water quality test on the website regurally show 1.05. I will test a hot tub as well, and my tap water at my home to see if I get a reading of 1 or so.

Thank you for the info on the gassing out, that makes sense and i will let the water run for 2 to 3 minutes.

After RO tank was at the waste water
Spot free tank was done by just dipping it into the tank itself (which may explain the 0 there)

The reason i am taking more of an intrest is our TDS in the Spot free has climbed faster than it has in the past after changing filters, which led me to believe something wasnt working right. I will let you all know more as we continue to fix this problem.

Thanks for the help so far.

Steve

 

[soapy]

Your spot free system should have a charcoal filter in it before the RO membranes. It is designed to get rid of the chlorine before any can get to your RO membranes and ruin them. In my area they only use chlorine when they find a problem in the city water line. Then they flush the lines with it to kill any contaminants.

 

[teamplex65]

We are also going to replace that filter.

I was always under the impression that the "small" 10" filter is only for sedmentary (chunks) in the water and the RO tank was for chlorine.

The chlorine at our water plant has ranged from .95 to 1.28 in the past 5 months.

I will update everyone on what I learn and any readings we do. We hope to make a drawing of the system and test weekly to look for problems.

 

[MEP001]

Spot free tank was done by just dipping it into the tank itself (which may explain the 0 there)

I explained already that the RO system will filter out the chlorine. Unless your membrane is toast, it will always test zero or very low.

 

[teamplex65]

You guys are very picky in how people word stuff on this forum.

I meant that since I took it from the tank instead of the hose actually dumping water into the spot free tank that "IF" there was chlorine getting by the RO system it may not show up if I just test the water in the tank. Our filters are going bad quicker than they should, and we are looking for possibilities. I understand the RO system is "supposed" to remove all chlorine, however if it was not and I tested the standing water in the spot free tank, then it may show 0, even if it was letting chlorine by.

 

[MEP001]

I was always under the impression that the "small" 10" filter is only for sedmentary (chunks) in the water

It is.

...and the RO tank was for chlorine.

What are you calling the RO tank? You should have both a sediment filter and a large charcoal filter before the RO system and membranes. Unless you have membranes designed to handle chlorine, there should be none allowed to get to the RO system.

Our filters are going bad quicker than they should

Are you referring to the membranes? How are they failing? Are they clogging or does the product TDS get too high to be truly "spot free"?

You guys are very picky in how people word stuff on this forum.

It's usually a matter of communication. More information is always better than less when trying to determine a problem. Correct terminology is important too.

 

[teamplex65]

I was calling the charcoal filter the RO tank.

The TDS meter was showing 90 last week. I have ordered a meter and will test it myself.

Our system looks like this

Tap Water -> Soft Water Tanks -> Charcoal Filter -> Sedimentary Filter -> 3 Membranes -> Spot free Tank

You are correct, terminology is correct. I apologize for that last comment as i wasnt refering to it correctly. The end goal is understanding better how the system works, and what tests and levels I should be looking for at what areas in the system. I am going to draw up a map of the system, and look for your guys knowledge on what the numbers should be at each point, and if I need to be testing for more things like p/h.

 

[MEP001]

The "numbers at each point" is very simple:

Soft water to the RO system (Zero grains).
No detectable chlorine after the charcoal filter.
30 PPM or lower from the membranes. (Manufacturers say 50 or lower, but at 50 it will spot).

Since you have three membranes on one system, I'd suggest adding an individual tap on each outlet so you can test product from each membrane. You could have a bad seal or defective membrane housing, or you could have gotten a defective membrane the last time you changed them.

I mentioned before that testing for chlorine in the RO reject is more effective - what you described sounds like a pool and spa test kit and those aren't sensitive enough to test for traces of chlorine.

 

[Washmee]

I would think that you want the sediment filter to be placed before the charcoal filter in this setup. It should be immediately after the Tap.

 

[Ghetto Wash]

We are also going to replace that filter.

I was always under the impression that the "small" 10" filter is only for sedmentary (chunks) in the water and the RO tank was for chlorine.

The chlorine at our water plant has ranged from .95 to 1.28 in the past 5 months.

I will update everyone on what I learn and any readings we do. We hope to make a drawing of the system and test weekly to look for problems.

Unless you have a combo charcoal system and filter, there should be a whole seperate tank for the charcoal. The charcoal removes the chlorine, then the filter (usually 5 or 10 microns) removes the (chunks), then the RO membrane makes the SF water. In that order. Without charcoal somewhere - either combo or stand alone tank - you will fry a RO Membrane.

Edit: sorry, some of this is duplcate info. I didn't read page two before posting.

 

[MEP001]

I would think that you want the sediment filter to be placed before the charcoal filter in this setup. It should be immediately after the Tap.

Actually it's preferred to have the sediment filter after the charcoal filter. There's no reason to protect the charcoal from sediment, but the charcoal itself can work its way into the water and into the solenoid, pump and membranes.

 

[Washmee]

Actually it's preferred to have the sediment filter after the charcoal filter. There's no reason to protect the charcoal from sediment, but the charcoal itself can work its way into the water and into the solenoid, pump and membranes.

Seems to make sense. I don't use a charcoal filter because I use well water. No chlorine to remove.

 

[teamplex65]

We have replaced the charcoal filter yesterday.

We went to a larger tank for the charcoal as well. I have 3 new membranes to put in but the guy that helped install the new tank said we should wait a week or two before putting the new membranes in. I really hate to wait that long since my membranes were already shot and we are making worse spot free now than we were with the old charcoal tank.

When do you guys recommend chaning the membranes after putting new charcoal in? I will also replace the sedimentary filter as well.

Thanks Everyone for the help so far.

Steve

 

[MEP001]

I've never heard of waiting before changing membranes. A charcoal filter's effectiveness is simply depleted over time. It doesn't have to "break in," and if it was flushed thoroughly and you have a filter between it and the membranes there shouldn't be a problem with charcoal particles getting to the membranes.

Did you ever confirm that chlorine was getting past your old filter or did you replace it and buy new membranes under the assumption that it was?