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Sump Baffles are Baffling

The Gnome

Feb 5, 2006
Hello everyone in the briny deep !

I was wondering if I could tap into the vast seas of knowledge out there that you possess in the form of a couple of questions.

I have a 125 g Oceanic aquarium with overflows that are plumbed through the bottom with 2 bulkheads on either end. I plan to use a 55 g aquarium as a sump/refugium, which I've also aquired recently. Herein lies the rub : the tank that I got is tempered, meaning I cannot drill any holes for my pump.

I plan to run a Predator ALS 3 Skimmer with an Iwaki 40RLT external pump powering it. I also purchased a Blueline 40HD for a closed loop system ... which is going to involve drilling one 1.5" outtake and four 1" intakes for the system. I also have 2 maxijet 1200's and two via aqua powerheads to work into this equation, if needed

I guess my main questions are:

? : How would you plumb the sump for both the Iwaki/Skimmer open loop and the Blueline closed loop without drilling the tank ?

? : How many baffles should I use and how big should they be, exactly ?

? : How would I contain the chaeto in the refugium so it could never get into my display tank ?

Before I get my 'hands wet' I hoped to get the opinions of more experienced sump designers ... especially ones who have dealt with this situation before. (Not being able to drill the sump)

My only other option, which would solve this problem pretty readily, is if I found someone who would trade a non-tempered 55 for mine.

Please throw me some feedback if you know the answers ! :confused:
There's no way that I know of to run an external pump without drilling the tank. You could always make a PVC "u-tube" that goes over the side, but you would still need some way to prime it. I think this would necessitate an equipment change: either a) an internal pump or b) a non-tempered sump.

Baffles are usually done in sets of three: over, under, over. This is done as a bubble trap. Usually your skimmer and your overflow drain are in the same compartment, and both of these can generate a lot of microbubbles. If your sump was just one compartment all those microbubbles would go right into the pump intake and your display would be full of them. Since the bubbles float, the over-under-over baffles seperate them from the water going into the refugium.

For the height of the baffles, that's where some thought comes into play. For all the sections in the sump except the one for the return pump, the water level will be controlled by the height of the baffle. You want to set up the sump so there is enough empty space to accomodate all of the water that will drain from the display into the sump in a power failure.

You shouldn't have much trouble with the chaeto making its way to the display. It clumps very well.

Remember that you don't need a lot of flow through the sump. 3-5x tank volume per hour is more than adequate. Especially if you're using closed loops (although I still haven't heard of any other cephalopod tanks that used closed loops).

Allright. I think I have a grip.

I hope you can see the 3 dimensional image that I just whipped up in paint ... but I think it explains my understanding fairly well.

On the left side, which is where the skimmer outtake and overflow drain would be, I created a 'bubble trap' with the water level gradually decreasing. I figured that if you placed the first baffle 1 or 1 1/2 inch above the third then the water should run down into the main chamber as gravity being the powerhouse.

The baffle on the right side, by where the return pump would be drilled, is to contain the refugium and whatever I may have in there from getting sucked up into the pump and spewed into my display tank. It's vital that nothing gets through because I don't want my liverock to be seeded with chaeto or culerpra.

Tell me what you think !


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The first baffle doesn't need to be any higher for the water to flow. The height of the first baffle only increases the water depth in the first chamber. Your skimmer should have instructions with it that specify how deep of water it should be in, use that for a guide.

Its actually beneficial for your refugium to be hooked to your pump: Amphipods will routinely take the ride upstairs and it will keep a healthy population of them in your display.

I aquired my skimmer from a local reefmaster who was upgrading to something much larger and more obtrusive ... which is a real accomplishment from this one. It stands like 4 1/2 feet tall and it didn't come with instructions. Its a downdraft skimmer, which means that the outtake from the tank would plug into the top of the skimmer and the water goes down and is pumped out the base into the sump. I hope to run PVC piping the whole depth of the first chamber and have an elbow at the bottom so the water has to travel from the bottom to the top of the chamber. I guess I could just drill both sides, and plumb up to the bulkheads for intake and outake at symmetrical places on the bottom of each end.

I think you're right about the amphipods ... I plan to house a bimac in this setup, after I aquire several hundred pounds of live rock ... piece by piece. It's going to be a while, but it will be worth it !

Thanks for your insight ! You really helped me out
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