I currently have a 125g tank setup (sand substrate, large semi-hollow rock in the center, driftwood and some small plants on either end, over kill filter.) and it is currently all nocturnal bottom dwellers (3x peacock eels: 8", 6" 4"; 1 galaxy pleco 5"; 1 striped Raphael Cat 5"). I want to have at least one green severum and 3 EBAs and a school of 12-15 tiger barbs. My question is, would this be too much for the tank (I do about a 15% weekly water change and my filter is meant for a 400g tank) and would these fish work well together? There are plenty of places for the bottom dwellers to hide (the eels all chill in the giant rock structure 99% of the time). Also wondering if they should be introduced gradually (if so what order) or if it would be better to add them all at once (fully cycled and established tank FYI). Any advice would be greatly appreciated as I'm planning on going tomorrow to acquire some of these fish!