I don't know that dilution works with the DPD test. And, you should test the tap water FIRST before you use it to dilute...if it has a chlorine level it will add it. Same for the Kroger water.

Distilled water is sold in every grocery and chain drug store, so it's easy to get. Also, OTO kits are sold just about everywhere. But the BEST that is sold in retail stores is at Leslies--it's Taylor's own OTO kit, in a Leslie box.

Another really good one is the HTH 5-way drop test kit sold at WalMart (may be called a 6-way drop test kit now). It's an OTO kit as well but it's tests for pH, TA and CYA are pretty much as good as Taylor's.

The FAS-DPD test is sold as a stand-alone test by Taylor. I believe it's the K-1515--and using it with the K-2005 for the chlorine test instead of the DPD test makes the K-2005 the same as the K-2006.

Cal-Hypo powder is sold in pool stores, including WalMart (but not the stronger stuff).

There are Leslies stores all over the Atlanta area, but only one inside the beltway.

It's not that I'm a big fan of Leslies--but that they are the ONLY ones that sell exclusively Taylor drop test kits, even when they are badged (and overpriced) as Leslies own. And the quality of their pool chems is usually good, if also overpriced.

Personally, I found a store years ago that sells 12.5% Liquid Chlorine (same as bleach only stronger) in 5 gallon carboys for $20. They cater to pool maint services so their turnover is tremendous and their stuff always tests at 14% or higher. I use that. They are a good drive but I combine errands when I go there--Orthopedist, electronics supply store, Harbor Freight, better Home Depot than my local one, etc.