You CAN get just the FAS-DPD test kit from Taylortechnologies dot com.

It's the K-1515-A and is about $25 as a stand-alone.

But it's the key test in the K-2006 we recommend. The others can be easily obtained in other kits (like yours). You don't have to replace your kit if you get this addition.

The K-1515-C is the same thing with a lot more reagents, and costs a good bit more.

I think Amatoind dot com sells the K-1515-C at a discount. lesliespools dot com sells the DPD powder and FAS-DPD reagent, but not the CC reagent.