Yes, liquid tester for your nutrients and soil probe for your soil. You can get away with just a liquid tester if you don't have the $ to buy both right now. You should always test and adjust your feeds to the recommended setting, usually between 6.3 - 6.5. You can then feed the plants and capture some of the water than runs out the bottom and then test it. If you soil pH is in line the readings going in and coming out should be about the same.
The test kits with the paper and solution are okay for testing your feed but because of the color changes that take place when watering, they aren't very accurate for testing run off.