Thanks, everyone, for the kind words. I'm really bummed about this.
I just am shocked about it. I know some fish are prone to jumping, but didn't really think this would happen with any of these fish.
That's a good point to always remember, Holly. I learned pretty early on about the abrupt lighting change; thankfully I learned about that from reading about that and not by discovering it through an unfortunate incident, such as happened last night.
I always gradually go down with the lighting in the room with the tanks. The overhead lights had been off for quite some time, I have a floor lamp by the tank, and that was on, but my laptop was right by the tank, too, and was brightly lit up, so when I turned off the floor lamp there was still light coming from that, and also I have french doors to the patio, pretty close to the tank, and I leave the patio light on all night, so a lot of light comes in from that source; the tank has a nice moonlit look to it from that patio light.
This Rummy was the biggest one of the whole bunch - so beautiful. Is this unusual to have a Rummy jump like that? Do I need to be investigating possible causes for this behavior? The Rummies are very timid and stay in the back of the tank, mostly. I am getting about a dozen tank raised Cardinals for their tank and hoped that they will help them feel more secure.
The Rummies always look very healthy, bright red faces. I keep the water quality good. I do 50% water changes every 6 to 7 days. The ph stays around 7.4 plus or minus .2 and the water is a bit harder than they would prefer, too, but I felt that stability is more important and I do keep it very stable.
They eat well. There has been no illness in the tank. I have been keeping the lighting more subdued for the last few weeks, around 1 watt per gallon overhead, I think the color/temp of that bulb is 6,000K. I alternate lighting periods with the floor lamp which has three CFL 60 watt bulbs, but it is off to the side and gives very indirect lighting. I guess total photoperiod would be 8 to 10 hours.
I feed them a couple of different good quality flake foods and also krill crumbles from kensfish.com, and, not often enough, I feed them FBWs. I have a SunSun 302 canister and an AC 70 HOB on the tank so it's over-filtered. I keep the temp pretty stable; it fluctuates between 77 at night and 78 in the day time.
The tank is planted, and while this is not exactly an exact biotope for Rummies I've read that they do alright with plants. I believe my Rummies are the "true" Rummy nose Tetras.
Thanks for your support and encouragement, all. Opinions welcome.
I hope this doesn't ever happen again. I feel so sorry for the poor little thing. He must have suffered an injury from that fall onto the hard tile floor. I think he was out of the water for about 2 - 5 minutes at the most, but i guess that, too, would be enough to cause sufficient damage to lead to his death.