Copepods population is dwindling?

[BlackTip]

I seeded my DT and refugioum with Tisbe 3 months ago. There weren't fish to consume them. Also, I got hitchhiker amphipods from cheato. At times I could see so many of them on the DT and QT glass. I used to drop algae wafers for them in the refugium, and once in a while phytoplankton. I'd shut the water flow to the refugium, put some phytoplanton and leave it overnight. In the morning, I could see the glass covered with copepods.

Lately, I don't see any copepods in the refugium and I see dead amphipods. I still see some live aphmipods though.

I was hoping to create good culture, before I introduce the fish.

What could possibly happen to them?

My refugium is a section in the sump and fed from the return line. Water flow is about 100gph. The nozzle is pointed at the surface for agitation. Light is 10W LED 5k flood light from Amazon. Light is on for about 12 hours a day.

 

[Ratpack]

You mentioned that you used to drop algae wafers in for them, have you stopped feeding them? If so, that is why the numbers dropped.

 

[laga77]

I would not cut the flow to the refugium, especially at night. You will be shutting off the oxygen. The phyto will be using up the oxygen in the dark. This could be killing off the pods.

 

[BlackTip]

You mentioned that you used to drop algae wafers in for them, have you stopped feeding them? If so, that is why the numbers dropped.

Algea starts emerging in the refugium, and I started feeding the fish and shrimps in the DT. So, I thought that would be enough for them.

I would not cut the flow to the refugium, especially at night. You will be shutting off the oxygen. The phyto will be using up the oxygen in the dark. This could be killing off the pods.

The reason I did that is to give them enough time to consume the phyto. Otherwise, it would be pumped to the tank and wasted.