Donnie,
Hey I have so info for you. Don't waste your money or your time to test your water for anything! If you are not losing other species besides BG, then don't mess with testing.
You are experiencing a problem mother nature is causing due to the weather. I am guessing you are losing either HBG or BG. They are more than likely between 4-8 long. I would be suprised if you are losing anything smaller than that. If they are all HBG, it is because they can't tolerate the winter like BG. So it is not unusual that you lose some each Spring.
If they are BG, it is the drastic changes in the weather. You have a shallow pond which is influenced much more by the weather than a deeper pond. Your BG are affected by being under fed from last winter combined with the current weather changes. So the question is, what can you do? Well stock not only more FH, but also Golden shiners to feed your fish. To give you an example, a 0.5 acre pond one should stock 10#'s (approx. 3000) of minnows and 5#'s (approx. 750) of shiners twice once in the spring and the fall.
I hope this helps!
