I have been told that running the bottom diffuser in the summer months also creates issues with the warming of water and trout. so consequently we turned it off, but i spose we should have run it occasionally at nite. Seems like a balancing act that goes on between water temp and oxygen levels constantly all summer. damned if u do and damned if u don't. Maybe lmb won't be so particular w/temps. Not sure if hlmb are available in this area. So disheartening when u go from 14" trout to nothing.
