My 64 litre tank is full of fry of varying sizes as I moved the female into a separate tank and she continued to deliver two more batches. I feel I need to move some out as the size difference is noticeable and the larger ones seem to vacuum up the food while the smaller ones stay near the bottom. The local aquarium shop has agreed to take them but not sure I can separate the sizes. Shall I move them anyway as the tank is appearing crowded?