Is also a good source for jar test information. Jar tests are best when scaled to plant conditions such as detention and velocity. I have found several WTP that had choke points in treatment that destroyed flocc and rendered jar tests useless until problems were eliminated. Special consideration should be given to flocculator and flashmix G factors, baffle walls and piping between basins. A lot of times a expansions will take these choke points critical and only a close review will identify problems. Also remember to always make fresh reagents from fresh plant chemicals.