It may have been closer to 800...I just know it was close to 1000. It's at 400 now and it's only been a couple weeks. I need to get a bubble counter maybe to make sure I don't have the CO2 turned up too much even though the fish seem fine. I thought that a 5# tank should last several months...not weeks.
I use size 9 o rings from lowes 2.50 for 10, no leaks in 8 months.Can you explain how you'd use two wrenches? I just crank down on the CGA nut and the cylinder is heavy enough that it won't spin if I'm pushing downward.
As for nylon washers, item # 360386799207 on Evilbay is 10 washers shipped for $4. Or do a search for nylon washer CO2. They come in that normal yellowish color, btw, not the red that you see in the pic.
If you mess with your reg a lot (like me), you may want to switch to a new washer before it's time to refill the tank. So even if you get one free with every refill, it's good to have extras.