Can they only be used with a pumped system?
Would this be any good for a simple AG system?
http://cgi.ebay.co.uk/VOKERA-HEAT-E...ameZWDVWQQrdZ1QQcmdZViewItem#ebayphotohosting
Would this be any good for a simple AG system?
http://cgi.ebay.co.uk/VOKERA-HEAT-E...ameZWDVWQQrdZ1QQcmdZViewItem#ebayphotohosting