Everyone has there own way of doing things and you should do what works for you. I used to have 8 pairs of angels breeding in bare tanks with only a slate to lay on. As Barrie said they were raised for generations with vitually only tubifex and they would spawn about every 10 days. Brine shrimp/ microworm, then tubifex. Never had white worm then, didn't need to bother. Found the place in Belfast by keeping my ears to the ground. They are around outfalls to the river which the Regional Councils are gradually cleaning up. Have a look around any regular outfall which has high protein. People think they live on filth but they only do well on high protein like blood from a freezing works. You will find a few around outfalls from a cow shed but you need enough for them to get starved of oxygen and seperate from the gunge if you are going to do it commercially, and I think those days are gone as we get more environmentally friendly.