I'm getting 1 bubble every 3 seconds on the Hagen CO2 now. I will watch it, and figure out how long it takes for the mixture to die down. As soon as it starts to slow down I will replace the mixture so that I can keep a fairly steady supply of CO2.
I'm noticing a bit of GHA on the leaves of the Water Sprite now.

It has diatoms, BGA, and GHA just on the mid-height leaves. Not the very top growing part, and not the bottom. The diatoms seem to be almost all gone now. What is the cause? New tank syndrome or poor lighting? Should I bite the bullet and get a (non-Asian) Oto?
I added another 100gph HOB filter too.
GHA, BGA, and diatoms:
FTS: