Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations Can I test for zooplankton?

I most certainly did this with Bill's guidance! I believe I bought 3 cultures of daphnia pulex from Carolina Biological supply. The first culture I seeded directly into my pond. The second culture, I seeded in a container with my pond water in it and kept it inside. The third culture, I seeded in a container with spring water. I initially used large containers filled with 2 gallons of water each (pond water [PW] and spring water [SW]). I did not use food in the PW culture as there was already some green algae (Bill had identified Dictyosphaerium subsolitarium as the predominate phytoplankton at the time) for them to feast on. The SW culture, I would add some yeast to a 20 oz bottle of water, then add a little yeast water for the daphnia to feed on.

After 5 days, the PW culture was doing quite well and had evidence of reproduction (if you looked real close, you could see them with the naked eye). The SW culture, on the other hand, I done killed that puppy by over feeding (a little goes a long way, you certainly do not want to cloudy the water). At that point, I pitched my SW culture, decided my 2gal of PW was far to big at this time, so I got micromesh stainless steel and filtered out my living daphnia to start 2 new cultures, this time 3 cups each, both PW and SW again (feeding far less in the SW culture this time).

After an additional 5 days, both cultures were doing extremely well, with evidence of lots of reproduction in both. I expanded both cultures at that time to 5 cup containers.

3 days later, I noted a new plankton species (2 of them) that Bill identified as cyclops. I likely had some super microscopic eggs in my culture, or potentially came from my PW as well. It wasn't a big deal, but I would use a dropper and slurp them up when I could, just in case.

1 week later (15 days from when I restarted the cultures in 3 cup containers) the PW culture had countless daphnia swimming around, so I seeded that culture into the pond.

3 weeks from that date, I seeded the SW culture in the pond. I continued to grow and expand this culture that entire 3 weeks to really put a large amount into the pond.

This all took place from the end of March to the beginning of May in southern Ohio for reference. About every week or so, I would try to do a 20% water change, using that micro mesh stainless steel so I wouldn't lose any daphnia.
With the SW culture that I was feeding yeast water, I would feed to make it just ever so slightly cloudy, then when it would get real clear, I'd add a little more yeasty mix in. Hopefully these notes can help someone!

As for water clarity, Secchi reading was 24" at the beginning of this, and pretty still hangs around there to this day (almost 2 years later). I will say the minnow and tadpole population is still extremely abundant (I have bluntnose minnows, spotfin shiners, mosquito fish, and fatheads [the fatheads could be dwindling, but that was to be expected for those slow pokes]).