So... What was the total cost on that CO2? Did you ever get a chance to show the injection system into the HOB filter? - S
For the basic rig, figure $130 for the regulator, $8 for the plastic ADA stand, $8.50 for the CO2 cart and a buck of Clippard parts. While the upfront cost is probably $30 more than the ADA or Hydor basic systems, you save meaningfully on each cartridge (say $6-10) and the breakeven point is 3-9 mos depending on how long the cartridges last. Also worth noting that the Leland regulator is potentially upgradable if you outgrow your nano setup (consider the similarities between the Leland and this insanely priced ADA "speed regulator
The solenoid costs $23. It's pretty neat -- tiny (< 1" in diameter), generates no real heat and consumes 1/10th of the power of a common 110VAC solenoid I looked at. And its cheaper than the $99 ADA solenoid or $30ish 120VAC one that some use (I think this one is also a Clippard just a different kind).
The Clippard needle valve is $11 and the check valve is $5. While there are (much) better needle valves this one is pretty cheap and the Clippard stuff screws right on to the solenoid. Of course, while I say that I did end up getting a Swagelok valve because the Clippard doesn't offer sufficiently fine control. You can get it to run at 1-3bps but differentiating between 1bps vs. 1.5bps is an exercise in patience that I don't have.
On the CO2 injection, I'll try to post a few pics soon, I've been distracted by what seems to be fishless cycling purgatory...21 days in and my nitrites have been flat at 1ppm for the last 10 days. Annoying.