Added some pea gravel to the Sand System

My original load of sand over time and under pressure of water has compacted, and some of the roots were starting to show, especially when I was digging my channels around the sides. I decided to add some pea gravel to the sides to see if it might help to keep some of the algae from forming. So far, it seems to be working. It's been almost a week, and there's no sign of algae on the new pea gravel. The water seems to be flowing just under the pea gravel's surface. Plan is working!

Added the pea gravel only to the sides where the water flows around. You can see the algal mat covering the sand in the middle. Much of that sand "flooded" before when the mat built up enough around the sides when it was all just sand. 

Things are looking good, despite the lack of sun.