Dear Dipankar,

Can you tell me more about the pond characteristics (water quality, depth, surface area) and what type of phytoplankton (diatoms, green algae, cyanobacteria).

I hope these links will be helpful to you. Report of United States Environmental Protection Agency could be informative. hope the following links could be useful to you. 

https://www.clean-flo.com/natural-algae-control/

http://www.ecy.wa.gov/programs/wq/plants/algae/lakes/ControlOptions.html

https://www.epa.gov/nutrient-policy-data/control-and-treatment

http://www.water.nsw.gov.au/water-management/water-quality/algal-information/prevention-and-control

One control method is dilute the water through pumping the fresh water to your culture pond without any using chemicals.\if it is freshwater pond dilute with fresh water, if it is marine water dilute with marine water.If you can dilute with filteresd water then the additional phytoplankton can not reach to your pond  and esistence will be gradully decrease with fresh water,

Biological control methods for control of algal bloom through bio-manipulation are ecofriendly methods that involve either top-down or bottom-up approaches.

These may employ top-down control of zoo planktivores by piscivores and bottom-up effects on algae by benthivorous fish. The principle is based on manipulations of a trophic cascade. As a result of the reduction of feeding pressure of fish on zooplankton, large species of zooplankton predominate, which are capable of keeping the phytoplankton levels down. The desired composition of fish populations can be achieved by harvesting non-predatory fish and by introducing predatory fish. Bio manipulation is usually not very effective in the case of highly eutrophic lakes and reservoirs where the total phosphorus concentration exceeds 100 µg L-1. Most effective examples of bio manipulation apply to relatively small water bodies because of a great difficulty to continuously manipulate fish populations in large ones. Also, the bio manipulation procedure cannot be considered as a routine method, since it depends on a number of circumstances and can be performed only with the participation of a skilled limnologist. 

Due to fisheries and economical interests, lakes or ponds are commonly overstocked by benthivorous cyprinids. Benthivorous fishes re suspend large quantities of

sediments, which enhance transfer of phosphorus and cyanobacterial cells in to the water column. Besides, they uproot aquatic plants and their excretion contributes to

phosphorus loads. Therefore the removal of substantial amount of benthivorous fishes is strongly recommended if control of cyanobacterial blooms is the aim.

Use of herbivorous fishes:

Potential method to reduce cyanobacterial blooms development is direct grazing by herbivorous fishes. Phytoplankton is the main food especially for the silver carp (Hypophthalmichthys molitrix) and partially also bighead carp (Aristichthys nobilis). There are some indications promoted by ecosystem studies describing the effective use of Nile tilapia (Oreochromis niloticus) in cyanobacterial bloom control.

Macrophytes and periphyton:

The presence of macrophytes in lakes and reservoirs is beneficial for many reasons. Macrophyte-dominated lakes are resistant to development of algal or cyanobacterial dominance because rooted plants reduce wind and boat-generated resuspension of sediments, provide a daytime refuge to algae-grazing Daphnia, and shade and therefore cool water in the littoral zones. Macrophytes also remove part of nutrients and act as careers for periphyton, which further removes quantum of dissolved phosphorus. Some macrophytes also release allelopathic compounds inhibitory to cyanobacteria. Especially, the inhibiting effects of Miriophyllum sp., Chara and Elodea have been reported. However, there is a nutrient-based stability threshold for a macrophyte-dominated state of the lake of about 50-100 µg P L-1. If the nutrient loads remains higher, the phytoplankton or cyanobacterial growth will still overwhelm. Reduction of P loads increases the probability that the cyanobacterial or algal dominated state of the lake can switch to the macrophyte dominated, clear-water state. However, there is a resistance of the lake to both, the increasing and decreasing nutrient loading. The macrophyte-dominated lake can maintain clear water even in the case of high nutrient load, while water quality in the phytoplankton-dominated lake may not improve even if the nutrients concentrations are substantially reduced.