[drw94]

http://www.mcmaster.com/#catalog/118/122/=h07ycu Its the laboratory clear tubing 4mm od, 2mm id. I have stopped using my doser as I started using kalk after my tank crashed, dosing needs not that high yet. While in use the tygon looked like it would work. The only thing wrong with the tubing is the ID is not the same at the original stuff. This is not a big deal as you just have to increase the dosing rate a little. But once you get it figured out you should not have to mess with it anymore. My suggestion is to have a few people go in on a buy. The tubing is cheap, but you can only buy it in lengths of 25 feet. That is way more that i'll ever use in 10 years. I sent some tubing to dan223 so maybe he will chime in and let everyone one know his opinion on the tubing.