These great pictures and information come courtesy of Jeff from California USA. The pictures are of his baby red-tailed gold jardini. The following contains parts of  emails sent by him.

I have 30 of them and am raising them so I can breed them. The attached photos are of babies that I got from Australia. The fish are being fed fly larvae, small crickets, mealworms, freeze dried plankton, bloodworms, and small pieces of fish from the supermarket.  They are not being given any hormones or other un-natural colour enhancers. Although the red colour will fade as they grow older. I feed the babies often and usually change 50% a week on the baby fish ponds for maximum growth.

Currently they are in two 300-gallon round ponds.  I have an environmentally controlled room with orchids and several ponds.  I keep the room about 75 degrees and heat the ponds at 79 degrees for the jardini. I am getting two more 500 gallon 72" diameter ponds for the adult jardini.  I find that the round ponds "fool" the arowana into thinking they are more like in open water. I am going to try to spawn them in the 500 gallon ponds. Each pond is filled with RO water with pH buffered to 7-7.5.  Each pond has 30-60 watts UV also.  It's a pretty good setup I think.