Well the answer for my sump has been sitting in front of me all along literally lol. The totes I use for mix water work pretty well for that and I have another that I use for a cleaning tub for rock which I've had upwards of 100lbs in all the way filled with water with no issue. I'm using the semi-clear 106 quart sterelite totes. I'll just double em up for each sump for added security. My only worry is leakage from the bulkheads in the sides if I do double these up....any thoughts on that?