My flowerhorn hump is shrinking what should i do?

[Al Cat]

i just saw him this morning with his hump(kok) smaller than it was before. is it because of the water temp?, could he be sick?, or is it because of stress? i have him placed in a 90 gal aquarium under my 100 gal aquarium on a dual fishstand. he basicly sees how big i am everyday and gets scared.

 

[LovinPhish]

I would say yes to stress being below in the bottom causing his kok to shrink. Best to place him on the top where the 100gal is or make a custom 90gal stand to have your fh be at a good height.
I have a double stand as well with 2 20gal tanks and the bottom fishes gets super jumpy. I went and bought a 3 tier shelf from home Depot with 30inches height, moved the bottom 20gal there and now they are normal now. Hope this helps.