Even with the wet/dry left out of the original post, adding a 1,000 gallon sump isn't going to help reduce the stress of all of the fish listed below living their lives out in the confines of a glass box that measures 48x18x24.
1 oscar
4 severums
1 jurupari earth eater
2 firemouth
1 common pleco
1 black ghost knife
4 blood parrots All of this in a 90 gallon tank and all fish are full size. jurupari is around 9" and the oscar probably 12".
he has 2 emperor 400 and 1 fx5 filter running the tank.
That's just f'd up, no other rational way of looking at this. I view people who keep tanks such as this the same as I view a crazy cat person that keeps 20 cats in their apartment. Even with a quality diet, and all of the windows open for plenty of fresh air, those animals are crowded beyond what anyone could consider being a healthy environment. Not just healthy to look at, even crazy people can appear to be mentally sound, and appear to be healthy, and we know how that sometimes turns out.
One of the most important things I had to learn early on in this hobby was to understand my limitations, and then have enough discipline to stay within those limitations. Some people get it, some never do.
Just because one can do something, it doesn't mean that they should.
Agreed, that has been a personal mantra of mine for many years.