To answer your question we will need somemore deatils: How big ist tank? Is there any fish other than seveums? If so, what is it? Do you have another tank (and equipment) to be used as a nursery? If so, what size?
Ideally,. you would keep fry in the tank with parents and let them raise their young. Ideally, to accomplish you would ensure no other fish is present, otherwise it will get severly harrassed by parents and/or will eat the fry. If you prefer to remove little ones and raise them separately, gently reocate eggs/fry to a bare bottom hospital tank filled with water from aquarium they were born in. Provide gentle filtration and water movement(box filter with some floss and carbon attached to an airoump works great). Raise temperature to 80-82F and when fry become free swimmin star feeding thm finely crushed flakes
