The RedSea kits are really expensive, I doubt for the home aquarist they are worth the money, but I've only had experience with API, Tetra-Test and Hagen Kits. I like API hands-down over the other two. However, I'm a big fan of Seachem and if the price wasn't too much more I would give them a shot for sure. The API Nitrate kit is a bit of a pain, perhaps getting the Seachem Nitrate kit, and possibly their pH kit might be the way to go since those are the two API kits I (and others I've heard) have the least satisfaction with.