dead pods in pod farm

So I have been trying to grow some pods in my otherwise empty 10g tank in the basement. I had a sponge filter connected to an air pump, and was dosing phyto every 2-3 days. Temp kept at 74 degrees. Anyway, last night I noticed that lots of pods/debris were accumulating on the sponge of my filter, so I shook it out in the water. This morning I noticed several dead amphipods floating in the tank water, and I can't spot any live ones. Ammonia and nitrites measure zero, nitrates measure 10. What went wrong? And what should I do from here? The copepods are so small I can't even see them/distinguish them from dust, so I don't know if everything in the tank is dead or not.

 

how strong was your flow from your air pump

 

Fairly weak flow - basically the air bubbled absolutely vertically from the base of the sponge to the surface of the water. There is very little flow in the tank.

 

By the way, just to be absolutely sure, I ran a copper test on the water, and copper measured zero - so that's not an issue here.

 

well judging from your set up then i cant see anything terribly wrong... im sure you have some live ones in there still and it will probably bounce back

 

pods shed like shrimp... you may have simply stirred up all the molts?

These things can take crazy high nitrates and phosphates and SG swings... I doubt their all dead unless there is some poison dripping in there from somewhere external???

 

No poisons that I know of. I guess my question now is, how can I know if anything is alive or not, given the tiny size of the pods?

 

magnifying glass.

 

update

Just an update. Looked at the glass of my pod farm today and saw several pods moving around. So the day is not a complete loss, and the farm is working after all. Yay!