Thank you, guys, but nope. Things haven't gotten better. Pretty gruesome and sad day here as we lost Bima too.
Bima has jumped out twice before successfully (and was picked up and plopped back) straight through the greenhouse film covering the tank. After we lost Sima in Nov 2018, I installed a net over the tank. Bima tried jumping out again several times between Nov 2018 and Apr 2019 unsuccessfully, broke, wrestled, and messed up the net... because I made a wrong decision and bought a cheap leaves netting for $20 (something I had used before extensively and found to be pretty strong for its lightness) instead of a stronger net, like a sports net for ~$200.
I had to get inside the tank and sew the net a few times and adjust and stretch it again and again so it hangs above the water. After the last unsuccessful Bima's attempt a few months ago, I didn't sew the net, nor stretched it but let it float on the water surface. It looked like Bima understood that the net is an obstruction and won't let it jump and stopped trying.
Then it tried today and succeeded. It jumped out through a hole that I didn't sew and made a new hole in the greenhouse film, of course, with ease. I found it too late. Plopped it back in the tank but it wasn't breathing anymore.
Lessons learned:
[1] Get a forever home first for an arapaima, that's be at least around 20,000 gal, more is better
[2] Make it jump proof with high hard walls above the water level
[3] Don't be cheap and lazy - buy good nets or keep sewing the cheap ones, you frugal and indolent idiot
Here are the last two videos of Bima and the post mortem photos. Last measure is 5 feet and 6 inches at roughly 3 years old (bought at 5"-6" the summer of 2016).
I think Sima was a male and Bima was a female (I may be wrong) and Bima has had a lot more red in its coloration versus Sima.