Any chance you have instructions on how to make one? I know I need one, but hesitant to buy one because of reviews I've read about the media they use.I made one out of a 16oz water bottle and ran the intake off the back for fresh air from my skimmer. It made my ph problems go away permanently. 7.8 for months to 8.2 steady in a week. Everything is showing growth now and 30% livelier.