Interesting to me that people are recommending you ditch the baffle idea!! It seemed standard to me, but now maybe I'll have to re-think my own future plans and just buy some filter socks.

As you were....

reef_raf I am a little surprised that you would run a 110 g sump just to put a skimmer, a couple of heaters, and a return pump in??? A 33g would probably suffice but this is not the answer to the question that started this thread.

1st chamber to hold the sock 10 inches with a baffle across the tank 1" off the bottom with the next baffle 1" in and 4" from the top. This would hold your skimmer if you planned to utilize the middle chamber yet now alow you any filter sock configuration.
2nd chamber 30" long with baffles going opposite of the first two. This would give you a chamber with 47g capacity. Down the road it would be great for refugium or DSB and would nicely fit a 24 or 30" pc light. But now can be for your skimmer and heaters.
3rd your return would be just under 20" giving you a return chamber of around 30+ gallons. Nice size and you could go a week without top ups.

With this sump you would have close to 20g free to hold overflow from the main tank in case of power outage. Also you would nearly add the same volume of water to your display.

I hope I helped in a small way with my 2 cents worth. I would definitely look to the future when building this as you have a sump a lot of people would love to own as a display.
Pics please when your done.
Kevin

Bigger the better for a sump IMO. I have a 180g sump :)

Well, I was looking for a 75g sump, but this came up at a good price, and well, more water is better in my mind. The display tank did come with a 33 sump, but I figure if I'm putting it downstairs, I might as well go big. It is a really nice tank though, it would make a nice display.

agreed

I run my sump baffle-less. Just use a filtersock to reduce bubbles going into the tank as well as clean any particulates. I have my euroreef modded with the gate valve and it doesn't release any fine bubbles into the sump at all.

Agreed. I have a 75g sump for my 210g reef & if I knew earlier I was going to be tearing down the fw setups, I would have set up the 6' 110g as my sump instead. Even with a 48" by 18" footprint, I find I run out of room in my sump/refugium.

What are you planning for an auto top-off, gravity or pump? My RO/DI res is about 25 gallons and I don't use a calcium reactor so I had an issue where my float swtich from the dosing pump would sometimes stick in the on position and as a result had a few floods. What I did to safe guard against this was I simply hooked it up to a timer so it only runs for a few hours at a time. I have it set for an intermitent 7 hours per day maximum so it keeps up nicely with the evap but can never overflow.
I don't know if this is relevent in your case but it's an idea some may not think of.

Greg, I have a bank of 5g containers that drain thru a float valve (gravity)