After DPD3 my water sample turn middle yellow

Hi,

last night I turned on Boost option on my Hayward electro chlorinator for 24h hours. This morning (15 hours later) I tested PH, it's 7.4 and that more or less OK, I tested than Free Chlorine and show only 3.6 ppm, I expected more because boost is on. Immediately After measuring of free chlorine I added DPD3 to measure total chlorine but water sample turned in middle yellow color and after 120 second of measure shows 0.0 of combined chlorine. o_OWater temperature is 26 Celsius or 78.8 Fahrenheit. My pool is indoor pool, salt water, vinyl. Anyone has similar experience? Maybe because of boost was ON I get false reading two times?

Thank you for suggestion
 
Last edited:

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
18,155
Northern NJ
This testing with your Pool Lab 1.0 Photometer Pool tester?

No one here uses that test system and the few posts we have had about it raise questions about its accuracy.

That said, boost on your SWG will not give you FALSE chlorine readings. They may be inaccurate though due to your testing methods.

Looking up the Poolmeter specs it says it can test Chlorine (free/combined/total): 0.00 - 6.00 ppm. My guess is with boost on your FC is above the range the system can handle.
 
This testing with your Pool Lab 1.0 Photometer Pool tester?

No one here uses that test system and the few posts we have had about it raise questions about its accuracy.

That said, boost on your SWG will not give you FALSE chlorine readings. They may be inaccurate though due to your testing methods.

Looking up the Poolmeter specs it says it can test Chlorine (free/combined/total): 0.00 - 6.00 ppm. My guess is with boost on your FC is above the range the system can handle.
Yes, It's Pool Lab 1.0 Photometer. Yes, in specs is written tester can test Chlorine free and combined. I will check today once again i documentation of tester. Testing range is from 0.00 - 6.00.
 

jetola

Member
Apr 27, 2020
15
Denmark
Remember, with the Pool lab 1.0 - you can mix your test sample with distilled water, to come around the 0-6ppm test range. Use 2ml of pool water and 8ml of distilled water - and multiply the result with 5. (or 5 & 5 and multiply with 2)