# JBL ProScan Strips and Chlorine



## alanchown (4 Feb 2022)

My JBL test strips are measuring an amount of chlorine. This seems unlikely, I use RO water (remineralised with equalibrium) and have dosed with Seachem Prime- are these strips really measuring Chlorine or are they not reliable?


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## dw1305 (4 Feb 2022)

Hi all, 


alanchown said:


> are these strips really measuring Chlorine


No, would be my thought.  If you leave the water in an open container for a couple of days (or add an air-stone to it for a couple of hours) and it still registers chlorine? Then it is definitely something else. 

I'm not a water conditioner user (I use rainwater) I'd guess it is a reaction with the "Prime".  Seachem won't tell you what is in "Prime", but you <"can make a fairly educated guess">.

cheers Darrel


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## alanchown (4 Feb 2022)

To be honest, I only used Prime after the test showed chlorine. It also shows chlorine in my RO (home made), which also has an airstone running in it for a day before using (just as a stirrer for Equilibrium). I suspect the readings are false.


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## dw1305 (4 Feb 2022)

Hi all,


alanchown said:


> I suspect the readings are false.


I don't know how the strips work, does it have a list of ingredients or an MSDS sheet? If they go pink? it is probably  DPD (N,N diethyl-p-phenylene diamine)

cheers Darrel


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## alanchown (4 Feb 2022)

Not that I can see. I suspect that although you pay extra for the Proscan strips, that they are identical to the bog standard strips.


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## ian_m (7 Feb 2022)

Prime is known to interfere with tests, thus you can't rely on any results for 24-48hours after dosing with Prime.

If you are getting chlorine readings in your RO then I would assume this is true, as testing RO is the one case you can use test kits as there are no interfering other ions/salts present.

Chlorine getting through is:

Due to poor quality RO pre-filter not removing chlorine/chloramine.
Using incorrect pre-filter, not all pre-filters remove chlorine/chloramine.  Some pre-filters only remove chlorine. Look for chlorine/chloramine reduction filters. 
Due to exhausted pre-filter.
Running too high flow rate through pre-filter not giving it a chance to work.
If chlorine is getting through RO membrane is damaged by the chlorine and should be replaced.
If chloramine is in incoming water, you might want to test for ammonia as well, as the pre-filter breaks down chloramine to ammonia and chlorine, and should absorb both before the RO membrane.

Learnt all this from a local fish shop open evening. They were mainly leaning towards marine and supplied RO water and explained how their RO system worked.  All filters and RO membranes had flow meters on and were replaced before exhaustion. RO water was stored in tanks and tested for ammonia and free chlorine. Prime (or equivalent) was always added just in case of test misread, as ammonia and chlorine will be deadly to marine fish (in fact all fish). Water was stored (24 hours ?) before release on sale.


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## alanchown (7 Feb 2022)

I have ordered new cartridges as it appears its been a while! However, I did see something in Google results, although the page it linked to didn't appear to be there, from JBL that suggested 'damp' could affect the chlorine reading.


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## hypnogogia (7 Feb 2022)

alanchown said:


> Not that I can see. I suspect that although you pay extra for the Proscan strips, that they are identical to the bog standard strips.


They are.  In fact you can buy the normal strips and save a lot of money.  My local MA did a comparison  and found no differences.


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## alanchown (7 Feb 2022)

hypnogogia said:


> They are.  In fact you can buy the normal strips and save a lot of money.  My local MA did a comparison  and found no differences.


I'm sure you are right. I would expect they are a pretty standard piece of kit. I get wildly differing results depending on wether I use strips, liquid tests etc. I rarely check and this was the first test I had done since last April.


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## Hufsa (8 Feb 2022)

Even amongst people who religiously use and swear to liquid tests, strips are said to be highly inaccurate. If you have to test I would go for a freshly opened liquid test. I say freshly opened as I have experienced repeated false readings from tests after only 6 months from opening.


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