I have a 10 meter lead on my O2 probe.

Agree with the Chemetrics test data being good enough.

I'm not just a "pond owner" though, and the probe also allows me to check O2 levels in the fish hauling tanks quickly. No way could I spend 5 minutes per tank testing O2 levels.

www.hoosierpondpros.com

[Linked Image from lh6.ggpht.com]
http://www.pondboss.com/subscribe.asp?c=4
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).