You won't have tabaco mosaic ;) your grows are nice ;)
It's magnesium issues with nitrogen toxicity and overwatering. Soon will have calcium lockout.
TM part is such an urban legend, that I am in shock still seeing or reading about it ....
@mrpinkgoo, man, your grows are FANTASTIC !!!
Just a bit either overfed/overwatered or too much nitrogen.
Btw in soil I don't believe in flush as solution, good dry out and right pH or nutes in - the only way.
If you follow good watering regime, good pH everything will go back, some leaves will stay damaged, soon rusty spots could appear.
Ecotrive BioSys is a good extra in such cases, 2-4 ml into a pot , rubbed into a soil or added to water will help your roots.
Looks pricey , but last long and does the job.
Great grow generally !