I have been reading some posts about fish not being active and not feeding too well. Before this 100 degree weather came the fishing was decent. I kept thinking that my bass were eating my perch and thats why I couldn't catch any, but since I can't catch bass either, maybe there is an underlining problem. I have read that maybe low O2 levels are causing my fish to be sluggish. Is this true? I don't have a O2 reader, so I am not sure of my levels. Where can I pick up an inexpensive O2 meter and should I waste my money. If it shows i am low on O2 I am screwed anyway.