Pond Boss Forums GENERAL QUESTIONS Muddy water Alum - strike one. Alum - strike two. Now what?

I've done two alum & lime treatments on my pond, and... nothing. I'm guessing I need to significantly up the ante on dosage but I'm afraid I'll use too much. Is it possible to overdose alum & lime?

Did the jar test. Started with 1/2 TBS in a one quart jar. Water was gin clear almost immediately. Kept backing down until it was down to a pretty tiny 1/16 TBS in the quart jar (i.e., 1/4 tablespoon alum per gallon). Still cleared in less than a minute.

Pond is quite small - only .15 acre, but averages 6 feet deep. So, about 0.9 acre feet. Ph tested at 7.5 to 8 before and after both applications.

First application was about 7 lbs alum and 3.5 lbs hydrated lime. Zero effect.
Second application followed 1.5 days later: 10 lbs alum & 5 lbs lime.
Noticed a few areas of flocking on surface shortly after... then nothing.
Alum slurry was well mixed and sprayed over entire pond surface, followed by lime slurry, which was thrown out using a dip can over entire surface. Aeration was kept off.

I have 33 lbs of alum left, and plenty of lime. Should I use all 33 lbs? Do I need more than 33 lbs? What happens if you use too much?

This pond was dug 2 years ago in heavy clay and has never cleared. It does not get any runoff water at all. It is well stocked with fish (hybrid bream, 6-8 bass, 2 catfish, 2 triploid carp). The jar test proved what the problem is, but now I want to fix it (without killing my fish). Help!