I filled my 20 lb CO2 tank today. Like I said in another thread, the company that fills my tanks charges the same price for a 20 lb tank as a 5 lb tank. This begs the question - should I invest in a filling system so I can fill the 5 lb tanks myself? I have two 5 lb tanks. Would it be more trouble than it’s worth to fill the tanks? I suppose I could sell the 5 lb tanks, and buy one more 20 lb tank. It sure is nice to have a small tank to take with me when I go mobile with a keg. Another option would be to sell a 5, buy another 20, and use the remaining 5 when I go mobile, filling the 5 with a 20. Have any of you fellow brewers gone down this road? What were your thoughts and decisions?