Drop check !!!

Search Evilbay or Amazon. http://www.amazon.com/Freshwater-CO...8&qid=1347814552&sr=8-8&keywords=drop+checker is the cheapest one on Amazon. 6 or 7 bucks shipped.

You'll also need 4dKH solution. You can get it from Evilbay, or just do a WTB here.

[Ebay Link Removed] <- $6 shipped with solution

I am just getting setup for a first planted tank and have been picking up pieces as I go. In fact today I got the 20 pound CO2 tank I bought months ago filled. Anyway that ebay link is to the ph indicator I bought.

EDIT: forum is not kind to my link so... search for "co2 indicator" and then sort by price+shipping lowest first and you get to it.