(not from the net!)
Wow! That about sums up the experience. We have a 100 L tank and a 24 L tank. In the 100 L there are 12 Neon Tetras, and 6 Neon Tetras in the 24 L. We set up the 24 L as a breeding tank. Lots of plants, water at 24°C, pH of 6.2. But we didn't have our hopes up. We got a suprise this morning. The Neons in BOTH tanks started to spawn. The 100 L is kept at 25°C, well planted and a pH of 7.2. We have other fish in there, so we keep it mid range for all the fish. With all that I have read about the Neons being very diffucult if not impossable to breed, we did not expect this. There are more eggs scattered in the large tank and sadly nowhere to move the fish to. So it will just have to be if they make it then OK, but if not :(. My husband and I got an eye full of the spawning. Their favorite place was the Micro Sword right in the front of the tank. The female would sit there for a minute, while the male would spar with other males, the winner would come over and nudge her into the plant, then rub up against her. It would be really fast, blink and you miss it. What an amazing site. My husband tried for several years to get his Neons to breed and had no luck. Then he wants to try again so we get a tank. I got over excited and got all of the fish for the tank before it cycled. (I didn't know better). We didn't lose a single fish. We have had no problems with fish or plants. Now we have babies on the way. I guess I'm just lucky for the fish. Moral of the story: they will breed if they want to and you can't make them. :-)
My experience with neon tetras is that they are very hardy. They are extremely fast when being harrassed. I have six in my tank. They have split into two groups, which is completely normal. But over time when they get comfortable they will often go off individually. They will often chase among themselves, yet with playfulness. They never stress any other fish in my tank. And few fish have stressed them. They share a tank with a Three Spot Gourami, a Red Blue Columbian tetra, and four Zebra Danios. Since this tank is fairly new. My danios often join my tetras. It is important to keep these fish in a tank with plants live or fake. I would strongly recommend this fish to experienced fish experts or beginners.
I can't resist making a little blurb of a story about Neons that a customer of mine passed on to me. He apparently had a very large community tank that housed your usual variety of fish, with about two dozen Neons. Well, over the course of time he'd noticed his school was being thinned out, but no bodies were turning up. He didn't have any large carnivores in the tank, not even Angels, so he'd no clue what was killing off the Neons without bodies, and continued to just buy more Neons. Nope, they hadn't jumped out of the tank either. Then, one night, he decided to see what happened in the tank when he turned the lights off. So he watched as the Neons went to sleep. When they do, they go off individually and sink to the bottom of the tank and rest there, looking somewhat listless and dead. Well, cruising around one of his rock displays came his 30 cm Pleco, who was just sucking up Neons off the bottom like candy! Needless to say, he didn't buy any more Neons after that.
I've been keeping neons for months now and I strongly recommend you not to get too excited about their fine look and give them a hard time by putting them into an inappropriate aquarium. The fact is neons are rather shy fish and they find it pretty difficult to live among bigger fishes. They have to move out of the "monsters" way all the time. So, before you go to the pet shop and buy a dozen of them, check if you don't have some pretty, fat, nice-looking Angelfish, Gourami or even Goldfish in your tank. Or you'll enjoy the beauty of neons for too short a time. They'll begin to mysteriously disappear an the rest of them will be stressed all the time, although you might not notice it.
I haven't experienced any problems keeping neons. They don't seem any more fragile than any other fish as long as you use a bit of common sense and don't try putting these small fish with larger species that might make a meal of them. Maybe the overly sensitive fish some people encounter are wild caught and haven't acclimated to tank life.
When I made the move to planted freshwater tanks 6 years ago, that's when I really started enjoying tank tending. I have a 900 L acrylic show tank in my living room and a 225 L acrylic in my parlor. Neons are by far the best single all around fish for planted tanks and everything should revolve around them as far as I'm concerned. They are hardy too. I recently moved the 225 L to its present spot without breaking it down. I drained all the water except for 2 cm - just enough for the Neons and algae shrimps to stay submerged. I saw several go belly up and had written them off, but 20 minutes later they bounced back no worse for wear, and not one was lost! I like to keep large schools of about 40 - 60 fish to keep it more natural looking. Rasboras make excellent tank mates for Neons also and I highly recommend them as they will stay in their own school and contrast nicely.