Here is a quote from another forum
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This type of fish is originally cross bred in Taiwan, and later on introduced to mainland China. So it makes sense that people there got some more advanced knowledge about this species.
From what I've read, they seem to be extremely easy to take care of and they are pretty good at breeding as long as you have one male and one female. If you search for videos of them almost all the videos are about their countless child fish in the tank. In the Chinese forum people are giving away babies of this species for free because they really don't know what to do with them.
And guess what's the price for each one in China? 5-10 Yuan. That is less than 1 dollar. And it really shocked me how expensive it is priced in US. But I guess it is only because they are newly introduced so sellers can overprice them for a little while, but certainly not for long, because these are really, really tough fish and can produce countless babies in a very short time.
And here are some of the information from some Chinese website:
Length: 5-6 cm (max) (they are called "minI parrot fish" in Chinese)
PH: 5.5-7.0
temperature: 25-28℃“