It could be exposure or it could be the old problem with HC-110 dilutions - not reading the instructions correctly. Quite a few people mix up dilution from concentrate with dilution from stock. If you dilute STOCK (i.e. the concentrate mixed with the specified amount of water) 1:7, you're OK. If you dilute CONCENTRATE (i.e. the stuff straight out of the bottle) 1:7 you overdevelop everything.(posted 8306 days ago)