found this when I was wondering the same....
Breeding
Breeding rosy reds is extremely easy; all they require is good quality food containing lots of protein and a photoperiod of 14-16 hours of light a day. A breeding tank of 10 gallons should be setup if you are trying to breed them. The water temperature should be around 75F-80F. Any overhanging rock or decor can become a nesting site, clay pots placed on their side work great.
Each male will stake out a territory and court female rosy reds. Male fatheads will turn dark in coloration with breeding and develop a fatty tissue and breeding tubercles (do not mistake for ich). A female may spawn up to 6-7 times before being completely emptied of her eggs. After spawning, the male will guard the eggs and chase away the female. The fatty tissue on the top of his head produces a fungus eliminator, which he will rub on his eggs. Parents generally do not eat their fry or eggs unless extremely hungry.
Females will be ready to breed again in a couple weeks.
If a male is not spawning, try adding another male to add competition and he may spawn.
Egg and Fry Care
Leaving the care of the fry to the male is perfectly acceptable. He will rub his fungus eliminating secretion on the eggs to prevent fungus and will care for the eggs until they hatch. After the eggs hatch and become free swimming, the male and fry pretty much ignore each other. Fry can eat finely ground flakes the moment they become free swimming, but microworms or BBS would be much better. The fry grow fast and will be ready to spawn in a year or two.
You can also rear the eggs yourself. Remove the eggs by plucking them with tweezers or by taking out whatever they are attached on. Put the eggs in a 5 gallon tank with aeration and methylene blue or Maroxy to prevent fungus. If you see any eggs with fungus, remove them with tweezers. The eggs should hatch in 2-3 days. Feed the fry BBS, egg yolk, microworms, or vinegar eel. They will also accept finely ground flake food, but live foods are better for fry.
