After further reading, it appears that my lighting is extremely high (~4.7 watts/gallon), and lighting at this level will amplify any problems caused by insufficient C02. It also seems that the consensus is that C02 levels are more of a factor then nutrient levels.

About a year ago I moved from a single strip compact fluorescent to a double strip under the misunderstanding that my algae problems and poor growth were caused by insufficient lighting. I spent a lot of money on an RO unit under the misunderstanding that these problems were caused by nutrient imbalances in the local water supply (specifically excess phosphate levels from orthophosphate).

In hindsight, I could have saved a bundle with proper dosing and CO2 injection. I wish I had stumbled across the Barr Report sooner!

Can't wait for that drop checker...