Re: Ok, my lesson learned the hard way.......
About the only time a flocculant would be better than a clarifier (which again, neither are usually needed since chlorine alone can frequently clear a pool) is if there is a substantial amount of debris in the pool as this could overwhelm a filter or require many backwashings. For those with the ability to vacuum-to-waste, it helps remove debris so that it reduces the amount of chlorine needed to clear the pool and reduces the number of backwashes needed.
Imagine the classic algae opening handled by chlorine as shown in this post. Here the chlorine caused the algae to settle to the bottom and after day 2 (early day 3) there was a vacuum-to-waste to get rid of what settled to the bottom. That sped up this clearing. A flocculant is the same principle, but obviously would only make sense if chlorine didn't have the settling effect and there was more debris than would be reasonably cleared by the filter.
The bottom line is that normally neither a clarifier nor a floculant are needed and that chlorine alone will clear most pools. Of course, even when using chlorine you need to brush the sides, run the pump 24/7, backwash or clean the filter if it gets too full, etc.
Richard
Re: Ok, my lesson learned the hard way.......
Last season I had the pool opened and clear in 24 hours. I took the cover off, got the pump up and running and then vacuumed to waste once. Refilled the pool, vacuumed to waste again. The water was crystal clear at opening, and vacuuming to waste made sure nothing got stirred up and suspended in the water.
This year for some reason it took me a lot longer using the same procedure. I think mostly because I closed earlier than normal last year and I opened later than normal this year.
After vacuuming to waste a few times there was still a bunch of stuff suspended in the water. Of course brushing made it even worse. Even with 24/7 filtration after 4 or 5 days it was only making a small dent in the clarity. I forgot about the DE in the sand filter tip until after I had added floc, but the combination of those 2 things got it clear overnight.
