We had a late spring. I'm just now opening my pool. I have a 24' above ground pool. I've had it 8 years. Since it's late in the season, we have a pool full of polywogs. What's the best way to deal with this? Also, the pool is green. I purchased Yellow Out. We had mustard algae last year and I used it then. It worked good. Now I'm reading here it's not good for the pool. What should I use instead? Also, I've never changed the sand in the filter. We're changing it this season. We're replacing it with ZeoSand. Should we clean the pool as much as we can with the old sand before replacing with ZeoSand? Any help would be greatly appreciated! Thanks!