PDA

View Full Version : How to test for chloramine


ostrow
07/13/2017, 07:45 AM
A number of factors have lead me to order a Hach test kit.

Some test the ro waste water. I don't get why. Others test faucet. Others the output from membrane.

What is the right answer here?

Gladmaker
07/13/2017, 07:57 AM
I don't know why test the waste water. I don't care what's in that. It goes down the drain. I can understand testing the faucet to see if there's anything to be concerned about.
I did not see any Hach that tests for chloramine.

bertoni
07/13/2017, 01:52 PM
I would test the water that I intend to use, which generally is the output, not the waste water. I might test the tap water as a sort of sanity test on the test kit itself.

ostrow
07/13/2017, 02:06 PM
I would test the water that I intend to use, which generally is the output, not the waste water. I might test the tap water as a sort of sanity test on the test kit itself.

Makes sense, thanks.

Reading more some say chloramine can kill ro membranes fast and I have had to change mine like every 18mo.

So maybe I should test at the input to the membrane (out of the booster pump)?

bertoni
07/13/2017, 03:45 PM
Membranes that could be damaged by chloramines should have a carbon phase before the membrane itself. I don't think that the membrane should have much trouble if the filter has prefilters that are changed on a reasonable schedule, but it's hard to know what's in everyone's tap water. Some membranes are fine with chlorine (the actual chemical that damages other membranes). I think that most of those are made with TFC, but I am forgetting my acronyms. What membrane is in your system?

ostrow
07/13/2017, 04:06 PM
I have a Dow Filmtec 75, with 2x carbon blocks in front of it. I swap the oldest and rotate up every 3mos or so. The cartridges are from one of the regular suppliers (I think these are from h20 or air/water/ice. One of those.)

ostrow
07/13/2017, 04:43 PM
Anyway total chlorine tested 0 out of booster pump.

I am not sure what the difference is with "free" but will test that soon.

bertoni
07/13/2017, 05:31 PM
I'm not sure what's killing your membranes, then. A water source with a lot of metals and some carbonate might do that. In that situation, an ion-exchange filter can help, although it might not be worth the cost.

tazzy695
07/13/2017, 05:44 PM
Another question is how much preasure is the booster pump puting out might actualy be to high causing the dammage

ostrow
07/13/2017, 07:31 PM
I'm not sure what's killing your membranes, then. A water source with a lot of metals and some carbonate might do that. In that situation, an ion-exchange filter can help, although it might not be worth the cost.

Well it's Chicago. Out water is pretty good. TDS of the source is only like 173. And if this were the case there would be hundreds of such problems from others.

ostrow
07/13/2017, 07:31 PM
Another question is how much preasure is the booster pump puting out might actualy be to high causing the dammage

Frankly I am more comcerned about the corals.

Vinny Kreyling
07/14/2017, 08:12 AM
Test tap water for reference, test membrane output for confidence of system.
A water report from the water supplier should tell you if they use chlorinates.
Usually available online.

ostrow
07/14/2017, 10:14 AM
OK so "total chlorine" measured 0. "Free chlorine" measured 1.4/5 = about 0.3

Hach CN-70 kit.

It is the water post-carbon going into the membrane.

I could not find a good explanation of total vs free carbon or whether this level is something I must address. Anyone know?

bertoni
07/15/2017, 09:26 PM
Sorry, I am behind on posting. I've been dealing with a mild health problem.

I am confused. I don't know how total chlorine could be zero, but there is free chlorine. I'll try to take a look at the test kit description. What are the units on the measurements?

ostrow
07/17/2017, 12:22 PM
Yeah I don't think it can be. Likely both zero or close enough that my search is best elsewhere.

Barro777
07/18/2017, 01:48 PM
Free chlorine reading, by definition, cannot be higher than total chlorine. Anyhow, if your water at the point of measurement contained chloramine, your total chlorine reading wouldn't be zero. Hence, there has to be something else causing premature membrane failure.