68 Gallon Rimless Reef Build

[gregzz4]

Besides the good advice given while I was writing this letter

What I don't know about is how much water will actually be in the return area constantly when the system is running... is there a way for me to figure that out before setting everything up?

You set the level in the return area yourself. Enough to keep the return pump from sucking air right before the ATO tops it off is enough to keep the system running. While this isn't an ideal situation, it will give you an idea of how much room you have for powerouts

If I have to increase my return chamber size the only way thats possible is if I reduce the size of the refugium. I don't know what the best or at least minimum size of refugium I'd need on my system. Or is it best to go as big as you can?

If you were to run only chaeto, you could go anywhere from 8 to 12 inches cubed. You want to run a DSB and I have no experience with them, so someone else will have to help you here

I really like how you did your sump. Very well planned out! unfortunately I don't have a lot of realestate to play with here.

Thanks, but I reconfigured it 4 times, so not so well planned out
I built, then tested, then re-built etc

I see you have a 16" tall tank. I suggest you use as much of that height as you can. You'll need to build a stand for your skimmer, but ...
You'll increase your return area by 2g or so, depending on the height of your baffles. This may be all the powerout room you need. Plus, this will increase your total system volume
Hopefully others with a sump similar to yours will chime in ...

What I did was decide what skimmer I'd want to buy in the future and made that chamber as narrow as possible. I also built it as high as possible
I didn't plan on a DSB, so I built a small hang-inside tank for chaeto (later I built it remote). This allowed me to have it be part of the return area which freed up lots of extra volume for powerouts and total return chamber size

[gregzz4]

This is why I hope others with a similar setup to yours will help out ...

Go as high as you can, but leave yourself enough room under your DT to get equipment in and out of the sump, and to remove your collection cup without hating yourself