How to harvest copepods?
They are very tiny critters. You could use a turkey baster to suck up some water from the refugium part of the sump and if your population is high at all you will have some in the baster. However, you don’t normally need to do that. Normally enough copepods will get caught in the current and get pumped up to your main tank without your intervention. As to whether 100 copepods is enough to get you started; it depends on a lot of factors. You need live rock rubble or macro algae (preferably both) for the copepods to attach to. 100 copepods isn’t many for a 110 gallon tank but if you put them in your sump and give them time to multiply it will be plenty. If you already have a mandarin in your main tank that needs the copepods 100 isn’t even a good start. Edit: If your sump is set up with a refugium you will be fine. A refugium section would have the dividers all the way down on both sides; the water will flow across the top of the section without creating current at the bottom and the pod
