# Sump design with a bit of physics!



## dxn283 (Sep 9, 2013)

Hello,

I'm still working on the final plan for my sump (newbie here and this is first build) and I can't find any info on best dimensions for baffles based on flow rate.

I want a wet dry set up and I'm ready to silicone in the dividers. Problem is, I'm worried that in my attempt to save space and maximise the bio filtration, I'll undersize something and end up overflowing the sump.

I've uploaded a sketch of the intended design into my gallery with the dimensions I'm concerned about labelled as A, B, & C. 

Aquarium Gallery - Wet dry filter plan

At the moment it's just a plain tank so the dimensions A, B, and C are all variable. I do have the pump which is 1500 l/h. Can I assume that the water flow from the aquarium into the sump will be the same flow rate as the pump's output?

My big worry is dimension A. If B & C are too small A will need to be increased. The bigger I make A, the smaller the volume of Bio Ball above water level will be. I also plan on having mechanical filtration before the Bio Balls. I'm sure the filter pads will also reduce the flow, therefore increasing A.

Any feedback would be appreciated as I've been pondering this too long now, I'm keen to get the sump finished and enjoy the aquarium.

Thanks

James


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## coralbandit (Jul 29, 2012)

Have you accounted for head pressure on pump?1500 l/h= about 400gph and with the hieght from sump to aquarium you may/maynot even get any flow.
I hate baffles in sumps they divide it to much and leave user with an actual 2-5 gallons available for evaporation(you'll be topping off every day!).


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## jrman83 (Jul 9, 2010)

Curious about where your filter pads are. If by chance they were to get clogged just enough to impede flow, will they not potentially cause an overflow? Also, doesn't the water coming off the bio balls need a drip space? Don't you want that for a proper air exchange? Most wet/drys that are built by filter makers have ample head space between the bio balls and collecting water. Can't remember seeing the bio balls flooded like what you have - not from companies selling them anyway. Just a thought or two. Design looks decent for sure.


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## dxn283 (Sep 9, 2013)

Thanks for the reply. The pump is rated for a height of 2M, it's lifting to 1.6M. The 1/2" PVC pipe Ts off at about 1M with ball valve to regulate flow between the two 19 gallon tanks above the sump

See the pic Aquarium Gallery - Plumbing finished.

Both tanks then drain directly to the sump via 1" PVC pipes. I've been test running with no problems regarding flow. I had sized it to turn over 10 times the volume of the two tanks but now I consider head pressure I suppose it won't pump the full 1500 l/h. 

As for evaporation, I live in Indonesia and the tanks are outside on my porch. It's so humid here, I've not had a problem with losing water. I'm also planning on having the sump plumbed in line with my other tanks as one big system, which is part of the reason I want the baffles as it would create a whole section for mechanical filtration. I've seen designs on the Internet with the water flowing straight onto the drip plate and into the biological filtration. Wouldn't that quickly get clogged up with solid waste?

Considering the above, do you still think I should change the design?


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## dxn283 (Sep 9, 2013)

Hi jrman83,

This is what is worrying me. I want mechanical filters, but the risk of impending flow and increasing the water level in the first section makes me see visions of coming home to a wet floor. I thought maybe if the first baffle didn't go all the way to the top, an overflow would just spill into the next section, bypassing the filter pads. Not ideal but would keep the system running until I spotted it and cleaned the pads. I would have to check and clean them regularly for prevention.

Where would you suggest having the mechanical filter and would you use filter pads?

You mentioned the bio balls. I had read 1/3 submerged. Do you suggest having the whole quantity out of the water? How high?

Thanks jrman83 and coralbandit for your feedback. I'm new to this, never used a sump before, appreciate the advice.

James


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## coralbandit (Jul 29, 2012)

If you are making your own drip plate you can drill a whole in it to fit a 1" pvc pipe.Have pipe raised an inch or so above drip plate and then if filter pads clog water will flow through pvc when it raises high enough.If the drip plate isn't super tight water can simply overflow it and then go to bio media.
I have had bio balls partially submerged without it being a problem.
Mechanicals should be before the bio media to avoid it(the bio media) clogging.


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## dxn283 (Sep 9, 2013)

I like the idea of the 1" pipe in the drip plate. Extra back up is always good. I plan to have coarse filtration and then filter pads in the first compartment before the water travels under the first baffle. With the 1" pipe in place, I could have finer filtration on the drip plate, safe that if it ever clogged I wouldn't have an overflow. The more mechanical filtration before the bio balls the better, I guess.

Thanks for the info


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## Raymond S. (Jan 11, 2013)

Perhaps someone on here will give you a link to what was on here a few months ago.
I can't find it for lack of the exact name it went under but there are lots of others here who might remember it.
There was a DIY post on a sump filter which used plastic buckets from cat litter for part of it's basic pre-filter
section and a 20G tank for the sump/housing. The bucket sat down into the 20G and the water drained into the bucket.
Looked simple to make and had room for a lot of pre-filter of your choosing and had overflow for safety.
But like I said...if someone here remembers it's location.
A "review" by a seasoned person would also be considerate.


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## coralbandit (Jul 29, 2012)

http://www.aquariumforum.com/f37/simple-diy-sump-filter-42406.html
Filter is still performing well and uses a mag 18 to return to tank.


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## dxn283 (Sep 9, 2013)

Excellent stuff, thanks for the link.

Shows how we don't need to over complicate things to get good results. I have a lot to think about now, I'll be starting work on it soon. I'll let you know how I get on.

Thanks again to those who gave advice

James


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