Amphipods are easy to get going and keep.

This lot is in the bottom of the bowl each time i clean my filter wool barriers and I have two that leave hundreds at times in the bowl.
Everything is sterilised that goes in my system, I introduced this lot from just two over three years back, for two years now, the place is crawling with them.





My amphs in large numbers exist in my algae area, millions of them, but my algae area was designed to help do away with ever needing water changes, which it does, but the amphs in mine need to be cleaned you might say, well the water they are in to use them as food so I do not get my caulerpa growing in my displays, you do not let caulerpa get into your display tank!
If you are to do that silly named “refugium” of which it is not, just get some chaetomorpha to grow with nothing else in there and use some phos reduction material else where and introduce the amphs to that chaeto and that way you can lift out sections of the chaeto and shake it over a bowl and pour in the amphs to your fish, no harm done.
Chaeto, if spores get in, it’s not invasive in the aquarium!
These poor guys were in my filter barriers, I shook them a bit before going into a wash with my work cloths and they fell out and more on the tiles, most are dead but some survived the two days while drying out.