You can use both Up and Down when trying to get your pH into range. I would suggest to use less next time so that you don’t need to use both of the solutions. Go drop by drop if you need to 
The little cheap kits that have a blue liquid in a small bottle (not the soil kit) are the better one to get first they tend to be right out of the box. Then get a cheap digital one and use that most of the time and when you are not sure if its right use the bottle one to make sure its still calibrated right. This works for me
The probe units are meant for soil and are never accurate.