PaPond - It is extremely rare and difficult for cold water algae types to grow in conditions of summer. It is very doubtful that you would need to innoculate your pond with some of these cool or cold-water algae types. Most ponds, especially northern ponds, have an abundant, natural mixture of species that grow and decline with seasonal cycles. It's hard to beat "mother nature's" design and resoursefullness. The current ambient and competitive conditions determine whether they start reproducing or not and how much reproduction takes place. It's sort of like growth of cancer cells in the human body; dormant until something triggers growth. The algae cells do not all "die" when the population declines or crashes. Many types just "hang out" as rare individuals, dormant cells or some have special resting stages or forms. These forms can then revive when conditions are "right" for regrowth and reproduction.
The only ponds that would benefit from algae inoculations or seedings would be those that have been subjected to repetitive herbicide treatments which tend to, in the long term, deminish the natural and diverse algal community of ponds.
