Hey my FAS-DPD sample turned pink again!

[wayner]

I have noticed that after completing my chlorine test if I leave the sample for a few minutes it will turn back pink and I will need to add another drop or two of 871 to get it back to clear. Do others notice this? If not then leave your sample for 15 minutes are so after you complete your test.

FYI I have a brand new Taylor K-2006 test kit and I manually shake the sample vigourously - I don't have a speed stir.

 

[Butterfly]

Yes, if it sits, it will turn pink again, normal. The tests are meant to be preformed in a timely manner

 

[tim5055]

You can ignore it. If you let it sit it will almost always turn pink again. Nothing to worry about and it means nothing.

 

[ranger_ric]

If you let it sit long enough it can turn shades of lavender and purple! Perhaps this should be in the directions.
I love my TF-100 and this website. They freely give me knowledge and power over my pool, AND they offer the best deal on testing equipment to keep my Pool sparklicious!! Thanks TFP!!

 

[wayner]

Ok, so the initial reading is accurate. Let's say I put in 15 drops into a 25 mL sample - so that means I have 3.0ppm of CL. If it turns pink again and if I need to add two more drops to get it back to clear then the Cl level is 3.0 and not 3.4 - that is what I was wondering about. Normally this doesn't matter but if you are doing something like an OCLT then that would matter.

 

[tim5055]

Ok, so the initial reading is accurate. Let's say I put in 15 drops into a 25 mL sample - so that means I have 3.0ppm of CL. If it turns pink again and if I need to add two more drops to get it back to clear then the Cl level is 3.0 and not 3.4 - that is what I was wondering about. Normally this doesn't matter but if you are doing something like an OCLT then that would matter.

No need to add more. In your example 3.0 is the answer

 

[ranger_ric]

I usually test in 10mL sample. I have a cool Taylor sample sizer that prepares it up for me. In a 10 ml sample you divide the drops by 2.

 

[JamesW]

Are you doing the CC portion of the test?