Here is a video of my celestial pearl danios. I do keep fish other than cichlids! I have worked out a pretty easy way to breed this species and get plenty of eggs. I spawn them in a 2.5-gallon tank with a false bottom made from a piece of plastic needle-point screen cut to fit into the bottom. A couple pieces of pvc on the bottom keeps the screen up enough to create a safe zone for the eggs to fall into. Over the screen I put two or three sinking yarn mops. When I set them up to spawn I use an R/O & tap water mix (about 50/50) that makes the water about 125 ppm TDS, KH 7 and pH 7.3, which has proven to be soft enough for this species. The tank is filtered with a very small Ista Mini sponge filter. I really like these little filters! They are the smallest sponge filter on the market with a weighted base. The air is driven all the way to the bottom where there is a built-in diffuser. The lift tube is small, so little air is needed to get a good flow rate.
I do not bother separating males and females before setting the danios up to breed. This species, if they are in condition, will spawn every day. I put 6 – 10 adults in equal sex ratio 9or close) into the spawning tank in the evening. The lights come on the next morning and the fish will start to spawn. 90% of the eggs will get stuck in the dense yarn, and the few that fall through go through the grate bottom. At midday I shake out the mops to see if eggs fall out (and through the false bottom). There are usually a dozen or so. I let the group spawn again for another day and then return them to their aquarium.
I add two drops of methylene blue and remove the plastic grate. I let the mops stay in the breeding tank. Fry will appear within a couple days. CPD fry are larger that you would expect for such a small fish, but I start them on paramecium as a first food anyway. At five days they can easily eat baby brine shrimp. After two weeks there are usually about 2-dozen fry growing up.
I let them stay in the spawning tank for a total of four weeks, and I do a 50% water change every three days. Then I move them to a 10-gallon tank. At 8 weeks they look like miniature adults and can be moved in with the colony. I try to set up a group to spawn once a month or so. I manage to give more than a few away at club meetings, but the production is enough that there are always a dozen or so adults to work with.