New to growing so I need help diagnosing a problem. Temps ran a little high for a few days, went to change the reservoir and check the roots and noticed a few brown patches. I use recommend amount of hydro guard for 3 gallons, Flora nutrients at less than 1/2 recommended amount. I have One medium air stone. I taped the tube on the bottle to eliminate light there and placed a plate on top of the pebbles in case light was getting in there. Noticed the leaves, crunchy around the edges. I try to keep the water between 68 and 71 degrees, but as I said things ran high in the tent one day, almost above 100 degrees. Should I increase the amount of hydrogaurd AND use hydrogen peroxide to treat. Anything helps and thank in advance.