Now I am selling my Tank (fresh water setup)

[mr_alberta]

That's a lot of stuff for a 40! I think you will have problems with all those pistol shrimp in your tank. I believe they are territorial so you may have problems there. Same thing with gobies. Unless you know how to sex them, you might just end up with a whole lot of dead fish. 8 fish in a 40 is really pushing your luck IMO.

So, you have 2x250GPH powerheads and 2x300GPH return pumps? Did I read that right? Just need some clarification.