Planted Tank Obsessed
Join Date: Jul 2009
Location: Chicago, IL / Philadelphia, PA
I had the exact same setup you currently have with the watts needle valve and asa adapter. The valve was very hard to open and close with all that pressure behind it. I would keep an eye on the swap n' shop for used regulators. Beverage factory sells inexpensive regulators, but try to get a two stage regulator if you can. You should do some serious reading about different regulators in the forums before you buy, you will save yourself big money with the right knowledge.
Jorge- You may be able to find some needle valves that will work for the application, but like you said, they are pricey and may cost as much as a regulator. Also for the best control of your bubble rate, you can not depend on a needle valve only. The gas pressure in the tank is decreasing slowly every second the valve is open when at a stable temp. A needle valve is not designed to deliver a constant output pressure as pressure in the bottle decreases. They are only designed to meter the flow of the gas. And why work with 800 psi when you could work with 10-30 psi? Gas flow is easier to control at lower pressures.