PH Tester - Ok I had 1 of those ph testers when I first started they were never very accurate and a PITA to adjust. I use General Hydroponics ph tester it's always accurate and easy to deal with and cheap 5 - 7 dollars that'll last for the year. The ph color in the pic is what you want.
Fertilizer - I tried once growing with Miracle Grow it works in the beginning stages but I never got it to grow to the end. Plants need more than what that fertilizer will give them. I've been using Verti-Gro for a long time now always had success with them. They have a sale going on now for the same fertilizer I've been buying from them.
http://www.vertigro.com/dealoftheday.asp
They have instructions on the package of how much to dilute in 1 gallon bottles You need strong 1 gallon containers not the flimsy milk containers. Both fertilizes need to be in separate containers. Instructions also include how much of the
nutrients should be added to the reservoir of which I never went full strength with. Now my growing season is from May thru October growing 11 tomato plants of which I only used a total of 1/2 gallon of each solution.
Watering - I never used that ring does it drip out or flow out? If it drips out increase the time double it. I take my black tubing and push it down close to the stem of the tomato plant pics below. Those plants grew so fast they came over the top of the cages and grew down below the cages easily over 10ft tall. I also shot a very short video of my Black Cherry Tomato plants that was loaded with forming tomatoes. It was shot after an extreme heatwave that lasted about a week. You'll see my feed line running from PVC pipe into the perlite. The leaves aren't perfect but the tomatoes didn't suffer from the heatwave. I will remove the video in a couple days.
https://mega.nz/#!oWhXUaoT!lBC6rTlGu...bDXf5um3pMFtEc