I'm sending this to the Plants list as well, so apologies to those who receive this twice. I've recently been installing an automatic CO2 system using a Tunze pH controller. The price of the pH controller was very reasonable but I was alarmed to see th price of the valve. The Tunze valve was 16,000 pts (approx. $75), I then talked to various people and found that there isn't very much variation in price on these valves:(. Sooooo, I had a look around my local hardware store and found that normal electro-valves cost around 6,000 pts ($30), better, but still no cigar considering the basically simple design requirements. I was, a little later, browsing through the garden section on my way to buying some peat when I came across Rainbird irrigation valves. Guess what? they're 3,000pts ($18). Admittedly they have a bore of 3/4" but I reccon that I can use an end cap in the input/output bores, drill the end caps to allow insertion of the CO2 tube, use silicone to install the tube and there you have it, an electrically-controlled gas valve for justb over $18. I had a look at the internals and they're all coated in plastic so there shouldn't be any problem with corrosion or interaction with the CO2. I'll need a transformer to supply the 24v current needed but this won't cost too much. Has anyone tried this route? I'd be very grateful for any info. that anybody has. Colin ------------------------------------------------------------------------- This is the apistogramma mailing list, apisto@listbox.com. For instructions on how to subscribe or unsubscribe or get help, email apisto-request@listbox.com. Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!