Beginner Gardening: Aeonium 'kiwi' declining fast, 0 by kwie2011

kwie2011 wrote:
This little Aeonium was growing quickly when it was suddenly hit by something. The edges and undersides of the leaves were damaged first, and within just a few days of the first visible damage, it was in bad shape. I'll post photos from March through yesterday so you can see how well it was doing and how rapidly this happened.

It is/was in a community pot with healthy Crassula, Graptopetalum, Echeveria, etc. None of the others have any symptoms. They were all in a 2:1 granite:diatomaceous earth grit mix, all particles around the size of cat litter. When the damage became noticeable, I moved them all to straight DE fearing dry medium might be contributing. The mix did dry out too fast, but I'd been watering 2-3 times weekly to compensate. I'll try to include a photo of the roots so you can see it isn't root rot or something. They're outside with 6-7 hours of direct sun daily. Temps have reached the low 90s just a few days, but mostly have been in the mid70s to mid-80s. Nights have been in the high 50s to 60s. They do not get rained on. I'm in western Oregon. They're on a second floor balcony so they're not being eaten by slugs or snails.

I have tried to ID a pest using a hand lens; a macro lens on a camera and then enlarging the photo; flicking the leaves over a piece of white paper and then examining the paper, but I can't see any bugs, eggs, honeydew, larvae, etc. Still, I feel strongly that this is a pest. I suspect a TINY mite that has attacked two other plants over the last year. The mite is much smaller than most spider mites and doesn't spin webbing, which might explain why I can't find bugs.

Anyone ever see this or know what it is?

Photos are
March 13 before it's growth spurt
May 29 growing like a weed
June 3 1st spotted damage
June 4 checked roots and repotted in straight DE because declining rapidly
Today - I've been spraying it with soapy water every few days