I would say it looks good as well. Just make sure you have enough room for additional water in the event of a power outage. Dont ever use check valves in hopes that they will work in the event of a power outage. They may work now but whos to say they will work once they are encrusted with algea and what ever encrusts our plumbing over the years. A simple L x W x D(in inches) divided by 231 i believe will yield you gallons. So lets say your tank is 96"L x 24"W x 24"D. And you believe that you will loose 1 inch of water if a power outage were to occur. so multiply 96 x 24 x 1 and then divide by 231. So thats almost 10 gallons of water. So you will need atleast 10 gallons of additional water space in your sump. You can use the same formula to find the empty space in your sump in the chambers to see if you have the space.
The only other thing I would suggest is to make sure you have adequate space in the return section for water fluctuations even if you plan on using an ato. You will need space for the return pump, so will need space for ato hardware(if you decide to use this either now or later), you will need space to accomodate water evaporation for a few days. If the section is small and your tank evaps a lot you will need to replace water more frequently either manually or remotely (ato). If you plan for a few days worth or more, you will give yourself more wiggle room for this. Also lets say in the future you decide to use a pump to circulate water from the return section back to the first chamber to help prevent water oxygen consumption and from being stagnent in the event of a power outage. If you gave yourself adequate space in the return section you will be covered. I know this is extreme, but it only takes one time for an event like this to occur that wipes out thousands of dollars of livestock in one power outage to make you think of things like this. So this could be extreme but then again maybe not. Good luck with your build.
