I have these growing outside in two plastic containers in the UK, I tried the whole pump in a container but no success in my attempts, my outside containers have been consistently providing, some small yields and some large, I have successfully kept a mandarin for nearly 5 years now (I do all this for him )
I used to order and pay for monthly copepods but my tubs are producing enough
In regards to sieves, you want a sieve that can capture the adults, at the moment I'm using a 250micron but I'm looking for a bigger/i would also advise on bigger, maybe 300-350
I suggest this as at the moment as feel 250 is too small and catching medium sized.. so not fully grown adults
Iif anything I hope this helps, but this is solely for my mandarin care and not retail,