thank you kuza
sorry to say but I think there are still too many larvae in the jar!
You will never get them all feeded. It is a "survival of the fittest" but if there is not enough food, even the fittest will loose after a time.
And there is too many dirt on the floor.
Rember: more larvae = more food needed. More food (artemia nauplii) = more dirt.
As wodesorel already said: the molt aswell. And they poop, too. Very much animals in the jar to make the water dirty.
Better to use only round about 50 or less in a jar
I only know that artemia nauplii lost their substantia nutritional value after 3-4 hours.
I could watch that they catch bigger artemia but they release them directly and try to catch a 'better' one.
All Artemia which are older than round about 5 hours are useless. And has to be catched out of the jar. Because they are additional pollution.
So in my opinion there is no need to feed them nor to keep them!
I clean my artemia jar every day with very hot water. And than I set up a new jar to have freshly hatched nauplia the next 18 hours. (mine are hatching very fast because they are INVE 430)
In the first days I set up 2 jars. To have new nauplii in the morning and evening. (in the case of the ocean nutrion artemia will not hatch). As an emergency food option
In the video it looks like that the pick up something off the floor.
They have something like hairs in fron of their head. They touch the ground and than they jerk and swimm higher. (The jar bottom reflect the light. And they always swimm to the light.)
As I already said: the can't pick up things from the bottom. That's what I see in each of my experiments.
What can be is: that their swimming arms swirl up the food from the bottom and than they can catch it . For me ti is too risky to put in frozen food. I have read in a fishkeeping forum, that frozen food can have a lot of germs. And has to handelt with care.
When they are in the megalopa stage you have to feed frozen krill, frozen mysis and stuff. But this has to be a very samll portion and has to be remove very fast.
The freshly hatched artemia nauplii are sooo small, it is very hard to see the larvae eat them. A good camera with macro funktion may help.
They definetly will eat freshly hatches artemia nauplii. So do not panic
