Oh alright, didn't see that.
And phosphates come from things like uneaten food, fish waste, sometimes the water itself if your not using RO/DI and most importantly, from decaying matter in the aquarium. The shrimp is decaying in your aquarium as we speak, so the phosphates you are seeing are coming from the decaying process of the shrimp. It's all in good health at this moment in time, and is part of the cycle. When the cycle is complete, doing water changes, getting macro algae(which uses up excess nutrients in your tank, mainly phosphates and nitrates), or using a phosban reactor(or some other phosban media) are all means of reducing the phosphates in your tank. Just worry about the cycling right now, and worry about the phosphates after your cycle is complete.