I noticed on another post that you don't recommend flocculant. However, it is the only thing that has worked for me, now 3 years in a row. I have 2 questions: if I add DE to my sand filter and/or add a skimmer sock, will this likely eliminate the need for flocculant in the future? (I use E-Z Clor Drop Out) Second question- I am now waiting for the flocculant to settle, then to vacuum. However, the brown gunk is collecting on the bottom of the deep end and along the edges and in streaks on the sloping sides to the deep end. Very little appears in the shallow end. (pump has not been running for 24 hours). Would it be OK to brush the bottom of the shallow end where there is not much visible sludge, and the sloping sides to try to move the sludge to the bottom of the deep end, then just vacuum the deep end. Will the sludge stirred up re-settle in the deep end, or will it re-suspend in the water and cause a recurrence of my problem? Vacuuming just the deep end would be quicker and waste much less water and chemicals. The last time I did a whole-pool vacuum it took out more than a foot of water. Re-fillling required about 5 bags of salt, several pounds of stabilizer, 5 boxes of borax and 2 gallons of acid. Thanks for your advice.