testing at high FC

[pollyAnna]

Hi we're mid slam so have our FC high - 25-30ppm. I put a range because my husband has done three tests and got three different results. Is this a known issue with high FC? Should we err to the lower number or higher? We've been using a syringe to get exactly 10ml sample and are using the proper testing kit as per forum recommendation.
any words of advice?

 

[JoyfulNoise]

You need two scoops of powder. High FC with to little DPD powder added can cause errors in testing. Try adding two scoops and retest. Also, make sure you are doing the test with a SpeedStir and that you are doing the test in under 1 min. Add the water, drop in the stir bar, turn on the SpeedStir, add the powder. Then immediately start titrating and make sure your dropper is vertical and you are titrating at about 1 drop per second. Record the number of drops as soon as the solution turns clear and don’t worry if it goes back to pink in a few seconds.