DPD tests

mrhappye

Well-known member
May 25, 2010
52
Fairfax Station, VA
I am new to this forum and have been reading many of the posts.
I have tested chlorine levels with DPD drops (Taylor) and DPD tablets (No. 1 and 3) that I have - I don't have an FAS test kit yet. The drops are fresh bottles.
With the DPD drops, I get a much lower reading than the tablets. The tabs can have a FC 3 and the drops 1. No CC. I brought a sample over to local pool store that uses the Waterlink Express and their value was closer to the DPD tablet reading. Anyone know why there is a discrepancy between the tests?
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,880
Silver Spring, MD
It is possible that your DPD drops have gone bad. If everything was working correctly they should agree with each other more closely than that.
 

mrhappye

Well-known member
May 25, 2010
52
Fairfax Station, VA
That was my first thought. Brand new bottles from the pool store. I don't know how long they have been there, but I assume they are from a new lot this season. Maybe I can contact Taylor with the lot no. I tend to trust the tablets more.
Thanx.