Cool discovery - making daphnia sink
So I looked around and I don't think anyone has posted this technique.
I have been feeding Hikari freeze dried daphnia to my green neons. The difficulty is that the dapdnia are like little air filled shells and they don't want to sink. My neons dont eat from the surface.
I tried releasing them underwater and they just float up before the neons even notice them. I have tried soaking them for several hours, and even then only about 20% would sink - the rest would float up and get lodged in the roots of my duckweed.
Lately I have been soaking the daphnia in a syringe for several hours. I would put in the daphnia first, then stick the tip into the tank, pull back the plunger and suck in some water. Then I would leave the syringe for at least five hours so that some daphnia would sink.
Yesterday I added some daphnia to the syringe. After adding water I pointed the syringe up and pushed out the free air. Then I let the daphnia soak for about an hour - just to soften the shells. Here comes the cool part. The syringe was about half full with water, I held my thumb firmly over the opening of the syringe (to make a seal) and pulled the plunger about 1.5" inches out. Of course this decreased the pressure inside the syringe. The air came right out of the daphnia and at least 95% sank!
I'm sure this technique could also work with any other dry food that is hard to sink.