Meters for nutrients, meters for moisture, they are worthless in my opinion. How can you reasonably expect a $10 retail meter to be accurate enough to give you a good evaluation of nutrients in your soil? That's silly.
What did it cost to make a $10.00 meter, .75 cents of parts and $2.00 worth of labor?
What you need to do is gain experience, get down in the dirt, you need to talk to your plants. They are talking to you. Their overall appearance, fruit production, flower production and growth rate will tell you so much more about your plants then a ten dollar meter.
I used Miracle Grow on the end of a house for 35 years on Long Island with fabulous results. Here in Michigan, I am using Jacks Water Soluble fertilizer for 2 years.
I fertilize once in mid April, once in early June and again in late July or early August, that's it. I water everything first in my beds and then again with fertilizer. 20-20-20 is what I use, 1 tbs per gallon.