Need An Accurate Tester For Chlorine

[moonlight]

I've been using Nat2 with MPS2 for a few months in my new spa. My eyes have been very irritated even after regular (weekly) shocking with dichlor and even draining and refilling the spa. Believing I might me allergic to MPS2, I stopped using it and switched to dichlor for a week. My eye irritation completely cleared up. To make sure, I went back to using MPS2 one time and got the irritation back. So, now I want to use Nat2 and dichlor on a regular basis (which the Nat2 instructions say you can do).

However, the Nat2 instructions are unclear about how to test for chlorine and what the reading should be. I called them and they said I would need to maintain the chlorine at only 0.4 - 0.6 ppm. They said I should use test strips for chlorine but did not recommend a particular brand. So my question is, what test strips are the most accurate for testing such a low amount of chlorine? Also, I've seen a digital readerby AquaChek. What about that?

I have used AquaChek test strips for mps2, TA and ph and found them to be very difficult to read and unreliable. So, I'm a little skeptical about a digital reader made by the same company. The Nat2 test strips (for mps2, TA and ph) are MUCH better and seem reliable. So that I don't go out and buy the wrong thing again I'd love some advice on what to get. I know, Nitro, you recommend the Taylor K 2006. Gee, it is so expensive and do I really need all that professional level testing? I'd love to follow your method but I'm so not chemistry oriented. I just have a 200 gal. spa. 1 person soaks every night for 20 minutes. Occasionally joined by a second for the same amount of time. No parties, etc. Just want to keep it simple.

Thanks.

[Elbyron]

I also found the Aquacheck strips to be very hard to read. Using a drop-based test kit is much better.

If the K-2006 is too expensive for you, try the K-1004. It's not as accurate as FAS-DPD, but it's far cheaper. I don't know how long the reagents will last me or what refills will cost, but it does seem to be a fairly similar cost to buying test strips. You could probably also buy refills of the R-0870 DPD powder and R-0871 FAS-DPD reagent seperately, if you wanted to have accurate testing without buying the whole expensive kit.

[moonlight]

Thanks. It's not so much the expense if it works well and is easy to use. I was hoping not to have a little chemistry set up going on. But I'll do what it takes to enjoy the luxury of soaking every night. I do have a little drop kit that the dealer gave me with my spa. Works for chlorine but not for the fraction amounts we are talking about. Also, it only measures up to 5 ppm and super sanitizing is supposed to measure 10 or 12ppm. So I think I need something different. Thanks for your suggestions, Elbyron. I'll check them out.

[chem geek]

If you want more accuracy (to within 0.2 ppm) and want to be able to measure up to 50 ppm, then the FAS-DPD chlorine test is the way to go. The least expensive option for this, if you already have a test kit with everything else, is chlorine test here from tftestkits.com (or you can get their entire TF100 kit). Note that the tftestkits have 36% more volume of reagents so are less expensive per test than anyone else.

[Matt87109]

If you want more accuracy (to within 0.2 ppm) and want to be able to measure up to 50 ppm, then the FAS-DPD chlorine test is the way to go. The least expensive option for this, if you already have a test kit with everything else, is chlorine test here from tftestkits.com (or you can get their entire TF100 kit). Note that the tftestkits have 36% more volume of reagents so are less expensive per test than anyone else.

Is it possible their site has gone down? It looks like one of those hack sites has picked up their address.

[PaulR]

yes, looks like they've been hijacked. I've bought from them a couple times, fastest service you can find.

--paulr

[PaulR]

They appear to be back up as tftestkits.Net, I was able to get to that site this morning.

--paulr

[chem geek]

yes, looks like they've been hijacked. I've bought from them a couple times, fastest service you can find.

--paulr

They weren't hijacked. The explanation is here. The domain expired without notifying the owner. So now tftestkits.net is the new permanent address though supposedly tftestkits.com will redirect there by Monday.

[Matt87109]

yes, looks like they've been hijacked. I've bought from them a couple times, fastest service you can find.

--paulr

They weren't hijacked. The explanation is here. The domain expired without notifying the owner. So now tftestkits.net is the new permanent address though supposedly tftestkits.com will redirect there by Monday.

Yeah that's what I meant when I said "hack site picked up their address", although I probably should not have said "hack". Anyway I just bought a TF100 kit. Thanks.

[moonlight]

If you want more accuracy (to within 0.2 ppm) and want to be able to measure up to 50 ppm, then the FAS-DPD chlorine test is the way to go. The least expensive option for this, if you already have a test kit with everything else, is chlorine test here from tftestkits.com (or you can get their entire TF100 kit). Note that the tftestkits have 36% more volume of reagents so are less expensive per test than anyone else.

Thanks, ChemGeek, I'll check them out.

I'm wondering, though, about the info given to me by the Nature2 people. 0.4-0.6 ppm is less than 1 ppm. According to you and Nitro, one should never let the FC get below 1 ppm. I know that Nature2 is supposed to do a great job of helping sanitize. However, I'm a little worried about these numbers. Any thoughts? I may end up trying to follow Nitro's chlorine/bleach method. Can't use Nat2 then, can I?

[chem geek]

That FC number is what you have in the spa at all times, according to Nature2, but there is no way you can maintain that sort of FC during a soak unless you start out before the soak with a much higher number of, perhaps, around 4-5 ppm FC. This is because chlorine gets used up fairly quickly during your soak oxidizing your bather waste (ammonia and urea from sweat and urine).

You can certainly use N2 with Nitro's Dichlor/bleach method and in fact it helps ensure that your tub is at least somewhat sanitary even if the chlorine gets too low. You will still need to add a lot of Dichlor or bleach after a soak -- N2 does NOT oxidize bather waste.

[moonlight]

That FC number is what you have in the spa at all times, according to Nature2, but there is no way you can maintain that sort of FC during a soak unless you start out before the soak with a much higher number of, perhaps, around 4-5 ppm FC. This is because chlorine gets used up fairly quickly during your soak oxidizing your bather waste (ammonia and urea from sweat and urine).

You can certainly use N2 with Nitro's Dichlor/bleach method and in fact it helps ensure that your tub is at least somewhat sanitary even if the chlorine gets too low. You will still need to add a lot of Dichlor or bleach after a soak -- N2 does NOT oxidize bather waste.

Thanks, ChemGeek. I'm slowly absorbing all this info.