I have the TF100 from TFTestkits.com, and have had for a while. No issues with the kit, but on my recent refill order I went ahead and got one of the battery powered string devices...
So I have a question, until I had this device, whenever I did the DPD test for chlorine, I used to swirl the cylinder between every few drops until the water went clear.
What I have noticed is a big different, in a reading in the order of 15 drops or more LESS when using the powered stirring device than swirling. So for example, 45 drops with the swirling, and 30 drops with the device until the water goes clear.
So my question is, which one is accurate. My concern is that with the mixing device, i've not had enough chlorine to properly shock whereas if the swirling method is accurate, then switching to the machine could cause me to use too much chlorine.
Thanks as always!