Originally Posted By: DKFarms
A pond is truly an interesting phenomenon. My turbid pond with 6 inches visibility, has over the past 45 days, cleared to a spectacular 34 inches, measured by secchi disk. No change in chemistry, tests are the same as they have been all summer. Only measurable change is temperature, average temp at 12 inches has dropped from 85 degrees to 80.5 since August 7th. Chara is thriving as it does every year with cooler water. So what happened? Did those multiple applications of Alum finally "kick in"? I'm as bumfuzzled as ever now, but it's a relief to see that the bass and bream have actually spawned. One day I'll figure this stuff out; maybe.


The Alum will not just suddenly "kick in" and I can assure you if the turbidity was from colloidal clay, there was certainly a chemistry change that had just never been measured. Unless your Ph was below 5.4 (which it isn't) the alum will not dissolve in the water and would have eventually settled out of the water column and was bound up in the sediments. With the little information we have on your pond, I wouldn't even venture a guess as to what caused the sudden clearing of your water...it's a stone cold mystery to me.