OTO minus FC = CC ?

[solarboy]

Hi, I'm new to this wonderful forum and have many questions, a few answers and am very impressed by the quality of information here. So my first question would be, I have a cheap OTO Chlorine test which I was led to believe actually shows total chlorine including chloromines. I have also recently started using test strips ( I know, I know a proper test kit is on my shopping list). I notice that my OTO test gives me about 10 ppm and the strips show 2ppm. I have zero CYA so am I right in thinking that I have 8ppm of chloromines? I'm quite happy to be ridiculed in the pursuit of knowledge

 

[duraleigh]

Hey, solarboy,

Welcome to the forum. :lol: I am not sure what kind of test you have. To my knowledge, OTO tests only go to 3 or 5ppm. DPD tests go to 10ppm but, by themselves, they can test for both FC and TC.

Help us get that figured out.

 

[JasonLion]

In addition to what duraleigh said: The OTO chlorine test does show TC, but it is wildly imprecise at TC levels much above 3. Similarly, test strips are quite imprecise at any level. So your results are suggestive of a substantial CC level, but really there is no telling.

 

[solarboy]

Wow what swift replies ! Being in Portugal I don't have such swift access to decent test kits but seeing as my eyes sting a bit while I've been swimming I'm guessing it would be a good idea to go through the shock process as described in "Pool School".
I have a choice of shock options however; I have 2kgs of monpersulfate, 5 gallons of H2O2 (I'm not seriously thinking of using this as I believe it will burn all my Chlorine) or do I just go and buy a jug of bleach?
This site has been quite a revelation after many Pool Industry sites. I've actually built about 10 pools but I've never got much beyond shock and drop a puck in and fit a SWG/pH pump.
Great site though, I'm going to be data mining for weeks !