daphnia is one of the most common live foods available sometimes sold dried these are useless but in there live or almost as good frozen form they can provide a great deal of fibre and encourage natural behavior they can be purchased in small bags from aquarists or captured from clean unpolluted water such as large lakes daphnia do not last in these conditions however they die mainly through starvation.
dapnia can be lept alive and by the same process be bred in large quantities by the following method
select two containers of at least 10g that let in as much light as possible(old tank,clear plastic tub etc) to get the best and fastest results these are best filled from a pond or waterfeature that exibits "green water" this can be mixed with old tank water to bring up the volume and add the nitrates that will feed the algea both are then put into an area were they receive maximum sunlight the idea is to propagate the free floating algea that will become food for the daphnia.
after a week give or take both tubs should be completely green , it now time for the dapnia to be added from whichever source is available about half coffee cup full for a 10g tub is fine less will take longer to bring up there numbers add dapnia to both tubs.
after another week or so you will notice the green water becoming clear as the daphnia feed now they can be harvested from one of the tubs depending on the fish to be consuming them,a course net will capture the adults and leave the smaller ones to grow when the numbers in the tank being used are few move to the other the low numbers of the daphnia in the used tank will allow the alage to bloom again repeating the cycle.
another use for these animals is to clear green water from a tank this is very simple if the tank contains no fish simply add daphnia and wait for them to clear the bloom if there is fish present a reasonable result can be gained from putting daphnia into a fine net breeder in the water current away from hungry mouths