Doing the DIY sump from a 20g long tank.

[fijiwigi]

Ok, I am doing the dang deal. Copying this design http://www.melevsreef.com/acrylics/sumps/glass/index.html
I will have the aquacrylics overflow/ Mag7 return pump/ and aquamedic turboflotor Multi. The 20g long tank is about 12" tall If I make the first 3 baffles (over,under,over) about 10". Will the 2 inches left of clearance be enough for when the power is out and the overflow drains into the sump. And With the turboflotor multi I am unsure how I will set it up in the sump.
And on the 3rd baffle do I really need to cut 1/2 inch teeth on the top?? How far apart should the baffles be from each other to get good flow threw I was thinking about 2" space between them. Then the last piece seperating the refugium from the return pump I will cut 4" acrylic with egg crate siliconed to the top of it. So it will flow from right to left. 1st skimmer comp then through baffles 2nd refugium zone 3rd section return pump zone with heater.
Anybody cut acrylic before that could offer any advice or any comments on this particular design would be greatly appreciated.

 

[MT79]

Where is the return chamber on that sump? If the overflow fails, it looks like the return pump would drain the whole fuge w/ that design.? If so that would probably flood the main tank.

How far apart should the baffles be from each other to get good flow threw I was thinking about 2" space between them

Generally they are spaced 1" apart.
FWIW I used a similar set up w/ a 20g high that is also very basic. The flow through the bottom of my fuge is very, very mild. I'm using 12" baffles. I don't have any complaints using a Mag 9.5. I'm able to run the pump wide open without micro-bubbles getting back to the main tank. I do run a SCWD on the return line so that kills some flow. Here is my fuge design if you're interested-
PS all the "over" baffles are the same height in reality.

 

[fijiwigi]

On the melevs reef website the first design you see is not the one I am copying if you scroll down there is an updated design. Your design is pretty much the same I believe except the return area baffle on the sight I was copying is a 4" high acrylic piece with eggcrate siliconed to the top of it instead of your second over-under. A 20g high tank would be good. Although I think with the long tank you get more refugium space since it has more length to it. I am still not 100% clear on how exactly the SCWD control device works it switches on and off from 2 returns to flow water into the tank to simulate a wave motion Is this correct???

 

[MT79]

On the melevs reef website the first design you see is not the one I am copying... the return area baffle on the sight I was copying is a 4" high acrylic piece with eggcrate siliconed to the top of it instead of your second over-under.

Looks like it's still going to drain most of the water from the fuge compartment should the overflow fail. You don't want the main tank to flood. The equation L x W x H /231 will give the volume in gallons. Size your return chamber according to how much water can be pumped back into the main tank w/out overflowing it. CPR overflows can be adjusted, so you can raise or lower the water level in the main tank accordingly. The overflow you mentioned is not from what I see. I think you would have to mount it on the tank to see where the water level will be when it's operating, and size your return chamber accordingly(I'm not familiar w/ them though). I would make the final "over" baffle the same height as the previous. If you look around melevsreef.com, you will find TONS of info.

A 20g high tank would be good. Although I think with the long tank you get more refugium space

I agree. I went w/ the 20 high b/c of space limitations.

how exactly the SCWD control device works it switches on and off from 2 returns to flow water into the tank to simulate a wave motion Is this correct???

You got it. If you decide to use one keep this in mind- Turning the gears in the SCWD, as well as the fact they only come in a 3/4" size, it will restrict the pump output some.