Well I do weekly water changes, but have been doing 5 gallons, I think 10 is more beneficial right now. I also have never thought to clean the back because...well...just never thought about it, maybe I will do 5 gallons from front of tank and 5 from back of tank from now on.
As far as the clumping and hard and such I can't really tell. It seems it has stuck to other algae as if to strengthen itself. I still need to get a CUC, and heater, but as mentioned before nobody around here has any heaters, so waiting on one now...Got a little ceramic heater in front of tank to at least get it near where it's needs to be until heater arrives. Will test tank here in a few min and post results.