Normal thrive is better because it has copper. Without copper plants will not grow. And you shrimp might not do well in water without copper. Since you don't know how much copper is in your water you should assembly it doesn't have any. So it is good to use a fertilizer with copper.
I just did a 80% water change in my tank. If your shrimp are healthy and breading and the new water is fertilizer the same as the old water they should do fine. However if your shrimp are not breading theyprobably are not healthy. In that case a large water change might be too stressful for them.
You should always use do weekly water changs. if you don't minerals levels in the water will gradually increase each time you feed your fish and shrimp. If you don't do water changes eventally the mineral content in the water will get high enough to make it toxic. The same is true with fertilized aquariums. Any nutrients your plants dod use can also build up to toxic levels.
Depending on the type of thrive you use and your does Thrive will add 1 to 3ppm of NO3 to your tank. Plants need nitrate to grow. My shrimp are fine at NO3 levels of 10ppm. The differences between all thrive products is insignificant when compared to what my tank levels are.
All thrive products are in
this fertilizer calculator. Simply enter your tank size, and select prmixed and then select the fertilizer you are interested in. Then in the box labeled I am calculating for select result of my dose. It will then list the concentration of each nutrient in parts per million (milligrams per letter).
All versions of thrive (except Thrive S) are classified as complete fertilizers because they contain all mineral nutrients plants require to grow. Thrive S doesn't have copper so it can not classified as Complete.
Leaf Zone is a waste of money it has only 2 out of14 mineral nutrients plants need to grow. There is no way it will work unless you have an aquarium with way too many fish in it. I have never seen a successful planted tank on any forum that was fertilized with Leaf Zone.