I've been real busy and haven't had time to check the roots, but to answer your other questions:
I change the
nutrient solution every week.
The reservoir size is 55 gallons.
I chill it to 68 degrees f.
I have 18 different heirloom tomatoes growing in the
ebb and flow system.
It is from greentrees hydroponics and the 2 bucket system keeps about 1/4 inch of water in the bottom bucket. When I cleaned out the system last year I realized the roots grow through the perforated top bucket into the bottom bucket, so there are some roots that sit in water constantly.
Do you think I should put an airs tone in the the reservoir?
Thanks for your help, I'm really hoping this is some kind of user error and not disease.