Hi bovsbaitboxes man long usid The best way I have found is to have your water hardness around 25ppm-50ppm very soft and keep them around 82 deg f have a spall flat rock any collor just flat and smooth I prefer dark can see eggs better should be placed in secluded spot with broad leafed plant overhanging rock when you notice female opivsor showing and belly fat and red do a 25% water change out of tap treated of course just cold this will do a temp change tword cold and signal it is time to spawn in wild spawning usually happens after rain should trigger the fish does mine have done it 5 times last 4 months problem is rams notorious spawn eaters this site will help save fry to sell has helped me http://www.aquatic-hobbyist.com/profiles/bredding/bluerambreeding.html check out my link in my sig Sincerely Curtis :idea2:
Beyond what's been said about water quality the main trigger for fish to breed is to be well conditioned. That is, feed them lots of nutritous food so that they will have the energy and reserves not only to produce eggs but to go through all the behavior with spawning. To get them to spawn I usually feed twice daily with live blackworms or other live food goodies. Keep up with filter maintenance and water changes to keep up with the increased amount of food (and therefore poo).
Also, while rams are substrate spawners and will lay their eggs out in the open, kribensis will want a cave. Clay flowerpots (unglazed) work well laid on their side.. the females will excavate gravel and sand to her liking and will generally wall herself inside the cave when she has eggs.
The main problem here with growing cichlids for a petshop is that you need lots of room and lots of live food to get the fry to sellable size in a short period of time. The parents will breed in 10 and 20 gallons, but the fry should be moved to larger tanks (I'd recommend at least a 20gallon of their own and larger if possible) to maximize their growth potential. Feedings of four or five times a day would really help them along.
There's a reason not many people are in the hobby to sell fish - its a lot of work for not a lot of pay!
From my experience, my kribs only spawned when they were in a comunity tank with the pressence of target fish, when I put them on their own they just attacked each other and looked off colour. They need a suitable spawning site, mine liked to use slate, they lay on the roof and sides of a hard surface. And they do tend to like a drop in temp after a water change