Hibiscus: Please Help! Something is killing my Belle, 1 by blupit007

blupit007 wrote:
I have many yellow leaves on my Belle du Jour. What can it be? I noticed tiny bugs while using a magnifying glass, on the underside of the leaves of some other hibiscus that I have, so I sprayed everyone. Actually I saturated every single inch nook and cranny on every plant I have 3 days ago with Bayer Rose & Flower insect killer. They all have been sprayed with this a bunch of times, as well as Neem so I don't understand how they are not protected. After I sprayed them, I let them dry, and the next day I blasted them all with the hose, top to bottom. Could this just be left over spider mite damage that will right itself? Should I now spray with Neem? I also have yellow leaves on my tiny Gabriel. And some starting on my Cajun Blue. I shouldn't have any nutrient deficiency, I use exactly what HVH suggests. Does anyone know what I'm doing wrong??

Several photos to follow.