Sump design. Critique please.

[Scott]

I'm building a sump out of a 30G standard tank (36x12x16). I'm trying to figure out the best configuration to meet my goals, which are:

1. Leave plenty of room to hold water with pumps off. My main tank drains about 3 gallons, though if given enough time, my corner overflow will slowly drain another few gallons as the standpipe isn't glued in at the bottom. (min 5-6G)
2. Maximize volume to be able to drain the sump enough to do an entire water change. (min 10G)
3. hold skimmer and heaters.
4. eliminate bubbles
5. minimize water that's pumped by the return in the case of a drain problem.
6. I need room in the return area for another pump or two for a few other small tanks (fuge, frag tank)

I do NOT want a refugium in here.

It's drilled on one end for an external return (thanks to JohnK).

After thinking about this all last night to take my mind off the disastrous super-bowl, I think I've settled on a simple configuration in the attached pic.

The left baffles trap most of the bubbles. Watching my current sump work, it seems that two baffles, over then under, do a good job at stopping most. (Goal #4) A third over baffle isn't needed since I won't have a refugium in the middle.

The large center area can be drained for water changes (goal #2). The drain and return areas could be drained as well if needed to get a few more gallons. So room in the drain area for a mag 5 would be a good idea.

The large center area can house the skimmer and other equipment (goal #3).

The right baffle keeps the amount of water pumped out to a minimum in case of a drain problem. (goal #5)

So, the question is, how high to make the baffles, and where to position them?

9" baffles positioned 4" on the left and 8" on the right will give me the following if I run the water level at 9":

o 3.7G in the return area = max flood, minus what's displaced by pumps.
o 11.2G in the center area = water change capacity (minus what's displaced by the skimmer plus what drains from the tank)
o 13G unused drain capacity for when the power's off.

These all seem to meet my goals, but am I missing any important factors or considerations? Or is it a good plan?

Having written this, it seems like the ulitimate dead-simple sump, but hopefully this helps someone else who is thinking along the same lines as well.

thanks.

 

[paulthomas]

Too much to read. I'd help if I could, but I know less than you.

 

[marco67]

I would increase the size of your first chamber and use it for your skimmer. your baffles as drawn would be great here as they would maintain a constant height and that will help with skimmer efficiency.

On the final set of baffles if you go to a set of three: low>High>low (over>under>over) you will get two benefits.
One is a final bubble trap, two is it will allow water at a lower level to flow out to your return pump.This will save your pump from burning up when your top off fails.

 

[Scott]

Thanks Paul, big help.

And thanks Marc.

With my design, won't the middle section be a consistent level? I was thinking put the skimmer there and send the outflow back over into the first section.

So you're suggesting that the final baffles be set lower, say 4 inches (or whatever)?

I hear you on having more water available to the return in the case of a top-off failure, but I'm trying to balance that possibility with the potential for a drain failure and not wanting to pump 10+ gallons of water into an overflowing tank.

I think I'd rather burn out a pump than have a major flood. I guess a float sensor on the tank would be the answer to that.

 

[Scott]

This is how I'm picturing what you describe, Marc. yes?

 

[marco67]

Yes thats what I meant,
To me that's the best of both worlds,
Consistent level for the skimmer
and pump saving should the level get low

you could also add a baffle to the skimmer set (same as the last set) that would keep a lot of bubbles out of the center section.

 

[paulthomas]

Thanks Paul, big help.

My pleasure. "I try to do what I can do when I can do it."

 

[Miller]

I'm glad that somebody that knows what they are talking about chimed in to help
::stashes sump design idea in back of brain for later::

 

[ZenMastr1968]

I know you're not interested in a refugium in this one, but melevsreef has a lot of good information on sumps in general along with some layouts. You can take the information for what it is and ignore the fuge parts....