add them when algae starts to grow. They have enough food then. If algae is growing you're prolly at the end of the cycle and they will be fine. FWIW, I add pods every 3-4 months.

How long does it take for copepods to reproduce?

How long does it take for copepods to reproduce? Copepods will breed quickly but it will take anywhere between 4 and 6 weeks before you begin to see the offspring swimming in your tank.

How do I know if I have copepods?

You might see some beige to reddish little dots that scoot about. They will resemble what you saw in the bag when receiving your concentrated starter culture. Those home aquarists who have a microscope have a distinct advantage in that they can find copepods of all life stages.