Good morning. I am planning on using a form of Z-Media this year once I open the pool. I see that you have to backwash the filter multiple times once adding the Z-Media to remove the dust, etc. My question is this....generally when I open the pool I have a bit of algae growth. If I am backwashing, won't this be drawing "dirty" water from the pool, causing difficulty to tell when the site glass is clear? One point I might add is that I do not currently have any sand in my filter. I removed it when I closed the pool last year.