I just looked over your pictures but figured its better too add the algae comments here for your convince...
I also see Staghorn algae developing a little on the last picture posted. That often occurs in areas first where there's little to no flow from your filter - Any chance you can adjust your filter outlet to circulate the whole tank more?
Also this very algae type is often seen in overfed tank and or clogged filters. So the question would be how much do you feed? Do you have any feed breaks (like only feed every 2nd day)? When you do your water exchange and have 'dirty' tank water in the buckets rinse out your filter pads in there every once in a while, not to get them sparkling clean, but to get the big 'chucks' dirt off, know what I mean?
When you do w/c do you just take water out of your tank or do you use a gravel vacuum?
Sorry my 'help' involves so many questions, I would just like to give you all info I can on the algae matter based of YOUR very tanks rather then a standard blah blah