Paul Sommers,

I saw your quastion about PH on the chat area....   

why would you want the pH up? 6 is not bad let your system mature, as it runs it will balance out... unless it keeps dropping then I would worry... part of the problem is the small size.. just like it is easier to run a 500 gal salt water vice a 10 gal system... watch what you feed the fish..   make sure you have not added anything (rocks decorations) that maybe the problem.... 

Paul, I saw your inquiry on chat about AP supplies for a classroom. I will be putting up a system in my wife's classroom this fall, a 5-6 class in a small private school in the Portland, OR area. I will base the system on a design from Portland Purple Water called the VEG system: Constant Height One Pump system- 50 gal fish tank, 50 gallon sump, 4- 25 gallon beds, made from food-safe barrels. the manual is $8, I think.

If you do it, and it seems appropriate, there may be some cool ed-ops to be harvested, classroom to classroom.  My first system, built with cannibalized props from her school drama productions, was planted last week. The fish go in next week.

Good luck. brant