Does R-0870 Powder ever go bad?

[DThompson55]

Starting a SLAM, testing for FC and CC using the TP-100 test kit, starting with R-0870 powder. The instructions say to fill the chlorine only vial with 10cc of pool water, then add a scoop of R-0870. If it does not turn pink I have no chlorine. And it does not turn pink. But the regular daily drop test kit shows high chlorine levels. And repeating the R-0870 test with straight 12.5% Chlorine doesn't turn pink either. Could there be something wrong with the R-0870? Can it go bad over time? Or could there be something wrong with the chlorine I've been buying?

 

[mknauss]

What color is the 'daily' drop kit test? The OTO one. If orange, your FC may be extremely high. What are you using to chlorinate?

 

[DThompson55]

I don't understand the question? The daily drop kit test is blue. The results are yellow in the 5-10 range. I'm not sure what OTO means? I'm using 12.5% solution to chlorinate, maybe up to around a gallon a day depending on what the drop kit test says. But I can't get the R-0870 based test to show anything. The instructions say if it doesn't turn pink I have no chlorine, but the drop kit test says I do have chlorine. So one of them must be wrong?

 

[mknauss]

OTO is the reagent you use for the comparator block in the K1000. So that was yellow?

 

[DThompson55]

R-0600 Orthotolodine with a yellow cap is what is in the K1000 kit to test Chlorine.

 

[mknauss]

Correct. It measure Total Chlorine. So if it is yellow, and your R0870 does not turn pink, then there is a possibility it is CC.

Add 10 ml of water to the chlorine vial. Add one heaping scoop of R0870. It it does not turn pink, add 5 drops of R0003 and see if it turns pink. If so, add R0871 to test for CC.

 

[DThompson55]

Ah - I get it now. It's a very subtle pink. It takes a good eye to see the change. I think I'm at 5FC and 1CC. I'm at 40 CYA, so adding about a gallon and a quarter of 12.5% to bring the FC up properly and then I'll see where it is in the morning. Thanks for your help!

 

[DThompson55]

Bottom line - I bought a fresh DPD-FAS kit from TFP ( best price I found on-line ) and all my chlorine measuring issues are solved. It turns vibrant purple the way it's supposed to, and it clears up to clear instead of going kind of muddy gray. So, hurray for new test kits!