Test kits are expensive in my opinion. The next one I want to get is a ph kit. Normally I test my water at the lfs. Should I get a ph kit, or a kh? Any suggestions. I already have a calcium, and phosphate kit.
I guess it can't hurt to have a pH test kit as a double-check, but since I keep an eye on it all the time I prefer to have a pH monitor or at least a handheld meter. Provided the electronic stuff is calibrated correctly it's usually accurate IME.
As for phosphates - personally I don't bother testing for them. IME you can see a phosphate problem (ie. rate of algae growth) long before you'll get a reading on most hobby test kits. I guess you could get a pricey, low range kit but personally I've never seen the need (JMO).
The only test kits I use regularly with an established tank are Ca, Alk and Mg.
I have a handheld one (made by Hanna) that I got from a lab equipment place years ago. It's this one, although this is not the place I bought it from (or the price - I got it cheaper): Hanna
I like the handheld one for the portability (useful for checking multiple tanks, livestock bags, etc.), but regular probe type monitors are more convenient for checking pH at a glance (and they're more popular in the hobby). Examples... Pinpoint Milwaukee