ACA Fish Stocking Pond Rehabilitation

Fishing pressure at ACA stocked ponds can exceed 2,000 h/ha in the summer months, indicating these ponds can be popular among anglers. However, our recent data suggests that some ponds may not be capable of supporting trout survival beyond mid-summer due to low dissolved oxygen (DO). Rainbow Park Pond is hypereutrophic (TP 101 ± 37 μg/L) and a good candidate for alum treatment owing to its high buffering capacity (alkalinity 132 ± 4 mg/L) able to withstand large fluctuations in pH. Alum treatment will reduce bioavailable phosphorus, thereby improving water quality and increasing DO concentration. Through alum jar tests, we 2 determined that a total of 25 mL (59.5g Al/liter solution) of alum per liter of pond water, applied over two treatments, maintained favourable water quality for fish and invertebrate survival (pH of 7.5, alkalinity of 72 mg/L) while significantly reducing total phosphorus (85% reduction).


Alberta Environment and Parks

Annual Summaries

We are working hard to upload all past summaries. If there is a report you would like to see that isn't presently here, please email

Title Year Category
ACA Fish Stocking Pond Rehabilitation 2018-2019 1
ACA Fish Stocking - Pond Rehabilitation 2019-2020 1