# How to suck from the bottom of your tank for a sump setup.



## chrispeck (Jun 4, 2011)

I have a 90 gallon tank with a traditional overflow. I really have not been impressed with the mechanical filtration in general, but more specifically the filtration of large particles and junk(such as fish poo). I thought that it would be nice to use a setup that sucks more from the bottom like a traditional canister filter does, resulting in excellent mechanical filtration.

I have been thinking about how to do this for my 200G tank for a while now. Tonight it hit me like a ton of bricks so I did a rough drawing to give a visual to my idea. The tank will have to be drilled on the back glass similar to a through the back type overflow (such as offered by glass-holes). You drill as close to the top of the glass as you can ( the top of your hole will determine your water level. You pipe right through the hole with pvc and drill a hole in the top of the 90degree elbow going downward. (MAKE SURE PIPING IS LARGE ENOUGH TO ALLOW FOR SUFFICIENT FLOW FOR THE PUMP YOU AR USING). Simply put a strainer of some kind on the end and set it as low in the tank as possible. the hole in the top of the 90 will allow the water to start the overflow, when the water gets down below the hole you drilled it will also not allow for siphoning, thus eliminating any chance for overflowing your sump(as long as sufficient room is left in your sump to allow for that amount of water).

please kick this idea around for a while and let me know what you guys think. I would like to get some feedback before I test this out. I will get a small tank for testing purposes.


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## nodima (Oct 3, 2002)

If that small hole in the top gets clogged by crud or something, and then the power goes out the tank is likely to empty.

You might be better off trying a different approach - either using additional current creators (power heads, UGJs) or trying to better 'aim' your returns so that water is driven up the tank walls near where your overflow is located.

For redundancy sake, I'd go with an additional filter for the tank. It is tough to get adequate performance from only a sump on a large tank, without resorting to huge pumps and overflows. As a data point, I have a Mag 18 on my 180, and I felt the need to add a couple of powerheads to increase the flow and move detritus towards one of the overflows.


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## bearrock (Sep 3, 2011)

I had the same issue. I swapped the standard returns for a spray bar that sits just below the surface (barely into the water so you can not see it or hear it) the effect was a current that pushed down the back side of the tank across the gravel and back up again. I would like to say I knew this would happen but it was pure luck  .

Since you are noticing the large particles I would guess you are using a white sand, if this is the case I would suggest either mixing with black, going all black or increasing how often you vac the tank.


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## CITADELGRAD87 (Mar 26, 2003)

I am attempting a similar exercise, but I have a built in overflow, so my setup has the return shooting UP from the bottom of the tank through a series of undersand jets, same idea but I would guess several jets would move more poo than a single intake? My jets are designed to circulate the water counterclockwise up and toward the intake gates.

My jets will rely on the same antisiphon hole that your shows, and I will be drilling a couple. I will just check the holes every water change and will be satisfied with that. I have no snails, so I am not going to worry about it.


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## Dragonkeeper (Feb 9, 2007)

A few hydor korlia pumps will fix this problem.


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## krfhsf (Dec 25, 2008)

Chris if that pvc on the backside was double elbowed back up to 1" or so below the surface. Then double elbowed back down to the sump. It will work. I have 2-200gal set up this way. when the water drains down 1" it will stop the flow. You will need a aqua lifter pump and air tube drilled into the pvc on the top pipe going over to the backside pipe(for prime). The flow is weak and you will want a surface drain too.


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## sprigsss (Sep 17, 2003)

I would add a t to where the drain line starts going down. That way you don't have a small hole that can be plugged. At the same time it could make water changes a sinch, because by placing a cap over the T you could drain the tank through the same line.

I've kicked around a similar design for quite some time planning for my next tank, but just haven't come across the right deal yet. Was planning on using a 55 gallon drum as a sump.


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## krfhsf (Dec 25, 2008)

yea the T is the way to go with the air assist . But when the water goes below the T it will stop the syphon every time. so I don't see how this would work for a water change. Maybe I'm missing something.


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## Rick_Lindsey (Aug 26, 2002)

You'd have to cap the vent if you wanted to use it for a water change, I really like it though! Then again, if I'm using a sump, I doubt I'll be doing the water change from the main tank! Just drain the sump empty (pump it dry?) and refill.

-Rick (the armchair aquarist)


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## sprigsss (Sep 17, 2003)

Rick_Lindsey said:


> You'd have to cap the vent if you wanted to use it for a water change, I really like it though! Then again, if I'm using a sump, I doubt I'll be doing the water change from the main tank! Just drain the sump empty (pump it dry?) and refill.
> 
> -Rick (the armchair aquarist)


Thats a good point.

When I was planning my setup, I was thinking I wouldn't be able to siphon the water out of the sump as easily. I guess you could always put a valve on the return line and pump the water out of the sump. I was thinking of putting a valve right above the drum along with a drain line and siphoning the water out of the tank.

I guess you could still do something similar but by leaving the pump running and flowing out the drain line, even though you are removing water from the tank you're essentially draining the drum.

Now you have me rethinking everything. Thanks!


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## chrispeck (Jun 4, 2011)

thanks for the suggestions. I am still mulling over what exactly I'm going to do.


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## zcfish (Jan 31, 2009)

IMO you do not have enough flow. How much actually flow do you have for the 90g tank?

For my 90g tank I run 600 gph actual flow there is some accumulation of poop in one area which I vacuum sometimes.

I run two pumps for my 325g tank (29" deep). 1000 gph actual each. One I run 24 hours a day the other 8 hours a day. I never vacuum the substrate.

Base on my experience sump is more efficient than canister filter when it comes to mechanical filtration.


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## chrispeck (Jun 4, 2011)

I have a 750 gph pump in the 90. for my 200G I bought a 950 gph pump, possibly to be aided by a couple powerheads.


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## nodima (Oct 3, 2002)

Agreed on your not having enough flow. My 180 is run by a Mag 18 which is insufficient by itself.


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## zcfish (Jan 31, 2009)

The size of the drains determine the max flow you can have. For example, a 1 inch drain can handle 600 gph max. Try to get to close to max flow rate. If you want to increase flow by adding powerheads, why not get a bigger pump.

Most of the pumps will have spec for actual flow rate @ certain head. Twist and turns of the plumbing will also reduce the flow rate.


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## dreday (Oct 12, 2007)

I like the idea but it has a few bugs to be worked out.

As for the flow, dont forget the flow from the return is probably your biggest culprit. Yes the drain is important but if you restrict the return you will notice a bigger shift then the drain. Most of the pumps will perform better if you use a larger diameter pipe.

Lets say you have a 100gph pump that has 1" outlet. If you use an adapter to 1.5" or 2" you will get much better return flow and decrease stress on the pump. Only if you need more head height should you use the regular or smaller diameter. That is the difference between the volume of water and the distance the water travels. Same principal when you are talking about air, only most of the pumps of blowers are listed as high volume low pressure, OR low volume higher pressure.

Either way you go match the plumbing all the way around, it will save you time and your mind.


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## toxicmegakitten (Feb 18, 2014)

Where you ever able to implement this??? I really like the idea, I want to switch from cannister to a sump, but worry that solid debris won't make it to the surface at any appreciable rate, leaving me with a tank bottom covered in fish poo. I think you could add 2 or 3 tiny holes to serve as additional siphon breaks as fail safe?


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## Narwhal72 (Sep 26, 2006)

I don't know if he ever tried it but it won't work very well.

The direct siphon from the aquarium will not be matched by the return from the pump. Essentially a surge system will be developed.

Most likely, the siphon will drain faster than the return, the tank will drain down until the hole is exposed, break the siphon, and possibly overflow the sump. But then the pump will start to refill the aquarium until the water level in the tank gets higher than the top of the U created by the pipe and restarts the siphon. Then the cycle repeats.

If the pump is returning water faster than the siphon can drain it, the sump will run dry or the aquarium will overflow.

Open type systems like sumps, must use an overflow in order to maintain balance.

To get rid of extra debris in a tank a circulation pump can create more turbulence which can get the debris up into the water column where it can be filtered out.

Andy


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