I calculate that my CYA is over 200 using the black dot method and using half tap water/doubling results. According to the (you all are right, they don't know much) pool store, my FC and TC is at 5-6. Clearly I need to add chlorine. My question is, should I be adding it while I'm doing the drain and fill? According to pool math, I need to replace nearly 75% of my water. I don't want to drain away my chlorine also.
Also, the only method I have to drain the pool is using my pool pump and diverting it through a hose before it gets to the filter. This works great until the level of the water drops to the bottom of the skimmer, then it just sucks air. I turned off the skimmer and put an orange (no tennis balls available) over the hole, but it still sucks air and causes the pump to lose prime. Any suggestions? I've resorted to filling at a slightly higher rate than I drain, also filling in the shallow end and draining from the deep end just to keep the skimmer happy.