# "Sump" level with tank?



## lucid_eye (Apr 12, 2009)

First of all thanks to everyone out there for letting me bounce ideas off your forehead. Secondly, I do understand what I am proposing is not a sump by definition.
As many of you know a pet store chain is offering tanks at a dollar a gallon. I am considering buying a 55 gallon tanks and using it as a filter. My 300 gallon tank is on a wall opposite my garage. My idea is to place this tank directly behind the the 300 gallon tank. I will use a pvc siphon from the 300 through the wall and into the 55. The top of the 55 will be either level with or slightly higher than the top of the 300. A 500 gph pump "that is already in the 300 and will stay there" will suck the water back into the 300 gallon via another pvc pipe that only drops into the 55 gallon as far as my desired water level(give or take an inch). This way if there is any failure (power, clogged line, ect) the worst case scenario is a burnt up pump.
So my questions are...........
Has this been done and if so what is your setup?
What major flaw have I overlooked?
Are All Glass Aquarium brand tanks drillable? If so I will set up an auto water change system with a stand pipe.
Thanks again,
Shawn


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## RRasco (Aug 31, 2006)

Interesting idea. I can't think of anything, right now, that would cause it to fail. It certainly would be easier to get quieter than a traditional overflow.


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## fox (Jun 11, 2009)

For the most part pumps push. Not saying there are no pumps that suck but the ones that do, do just that, they suck.

You want the water to be mechanically filtered before entering the inlet to the pump, if you set the pump in the DT the prefilter will be clogging with detritus if you have messy inhabitants.

Maybe a schematic of your design would be helpful but what you describe sounds like a closed loop system.


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## RRasco (Aug 31, 2006)

The way I figured he was talking about it would be to put a tank level with the 300, use a setup similar to a hang on back overflow, but instead of draining the water to a tank, have it pass through filter media and then to a return chamber where it would be pumped back into the main tank. This would effectively siphon the water from the main tank, filter it, and return it. Since both tanks are level, the pump returning water will lower the 'sump' water level, making the siphon water continuously from the main tank.


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## lucid_eye (Apr 12, 2009)

RRasco had a perfect analogy, it is basically a massive HOB. I was placing the pump into the 300 gallon because I always heard that you want the restriction on the pump inlet and not on the outlet. And there would be several baffles of filtration between the "filter/tank" inlet and outlet, so detritus would not be an issue. I am still in the brainstorming phase, once this thread has enough holes shot in it, I will begin making drawings with corrections.


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## fox (Jun 11, 2009)

The way I read it he was putting the pump in the 300 and sucking filtered water from the 55 back into the 300 thru PVC and siphoning back to the 55. That is why I suggested heprovide a schematic of his idea.

I posted that pushing was a better use of the pump and he might be better served pumping from the 300 and siphoning back to the 300 from the 55, thus the need to prefilter detritus. Either way I am not too fond of this and some brainstorming might be a good avenue to persue.

To the OP you heard wrong. You do not want to restrict the inlet side of the pump, it is the outlet that you restrict if necessary to control flow with mag drive pumps. With positive displacement pumps on the outlet side you tee off to divert any excess rather than restrict flow. You want no restriction on the inlet side, cavitation is bad.


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## lucid_eye (Apr 12, 2009)

Well that will work as well, I will place the pump in the 55 with the inlet rising to just below the desired water line. I will post a diagram soon.


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## RRasco (Aug 31, 2006)

Fluid dynamics make my head hurt.


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## Rick_Lindsey (Aug 26, 2002)

I suppose burning out a pump due to sucking air is better than spilling a hundred gallons of water in the house, but I can't help but wonder if there's a better way?

How far apart will the 55 and 300 be? If you're treating it like a giant HOB (verra cool!) then what bout building an overflow trough, much like an HOB, so you've got a wide uncloggable path for water to spill out of the 55 back into the 300? Of course this might involve cutting glass on the 55, and I don't know if the $55 55gallons are tempered or not. I've heard that one manufacturer (i forget which) tempers all panes on a 55, but i'm pretty sure another only tempers the bottom.

-Rick (the armchair aquarist)


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## lucid_eye (Apr 12, 2009)

they would be less than 6inches apart, basically there would be an interior residential wall between them. a 2x4 and 2 sheets of drywall. If I can drill the tank that would be Ideal.


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## jrf (Nov 10, 2009)

Interesting idea, I think it could work. However, you might have issues keeping the tank temperature below an acceptable max if your garage gets as warm as mine does.


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## Rick_Lindsey (Aug 26, 2002)

It'd be like an overhead filter, only it's really not overhead. What do you plan to put in the not-sump for filtration?

-Rick (the armchair aquarist)


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## RRasco (Aug 31, 2006)

This is what I was thinking...it will work just like a regular overflow, when water stops pumping, it stops overflowing...


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## Rick_Lindsey (Aug 26, 2002)

Cool. I was actually envisioning the other way... return pump in the 300 pushin water to the 55 which flows back either through some tubes or even a big spillway. That way if you ever do have some crazy catastrophic blockage (much less likely in the filter than in the tank) it'd spill in the garage and not the living room .

Of course this limits your wet/dry options since the 55 will be constantly full, and it's more like a HOB where the water level changes in the main tank rather than in the not-sump.

The more i think about it the more I like your approach .

Be sure to let us see the results when you get the beast built! Always a fan of unconventional filtration.

-Rick (the armchair aquarist)


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## lucid_eye (Apr 12, 2009)

that's basically the idea rasco but I know the 300 gallon is tempered glass so I would have to get creative. The reason I like the pvc siphon line is the simple fact that it works both directions, as long as it doesn't get clogged or air doesn't get trapped, the water can flow both directions and keep either tank from overflowing. 
Here is a basic drawing.


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## Rick_Lindsey (Aug 26, 2002)

Is there any reason to have the 55 higher in this case? Just be aware that the water level in the 300 will likely rise when you flip on that pump... how much it rises will depend on your overflow design.

-Rick (the armchair aquarist)


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## lucid_eye (Apr 12, 2009)

Rick: as far as media goes, 20 gallons of biomedia, 20 gallons of baffles with less and less coarse sponges/floss. I am also considering using a power head in the 55 gallon to spray a hydroponic tomato garden in the upper portion of the tank/filter.


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## RRasco (Aug 31, 2006)

Whatever form of overflow you want to use, I'm pretty confident it will work.


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## fox (Jun 11, 2009)

I am not sure the siphons will act as a compensator circuit in this case. Suppose this ...

The pump is pushing water under pressure and the siphons are working with diferential heights... the more the difference the more the flow but under gravity and not pressure.

Eventually it will compensate and equalize to a balanced height... not necesarily equal heights in each tank but rather a balanced height between the force of the pump and the siphons ability to compensate for difference in hydrostatic pressure.

Are the siphons going to be placed in a weir?


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## lucid_eye (Apr 12, 2009)

I understand what you are saying, but once I get everything up and running shouldn't that balance you speak of be a constant. If I start up the pump and let it run for an hour, and then mark the water levels, I should know what I am working with from that point on.
I don't plan on using a weir, it seems to be an extra piece that could potentially fail, that I don't need. Are you suggesting I do need one?


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## fox (Jun 11, 2009)

Mebbe compensator circuit was not the right word and comparator circuit is.

Either way the siphon is going to analyze both tanks and determine which has the greater hydrostatic pressure and the the water will flow to the tank with the lesser resistance ... all the while that pump is going about its buisness pushing 500gph in one direction without caring one way or another.

Really only one way to tell and that would mean fire that puppy up and lets see what happens. :thumb:

Not sure (1) one inch siphon tube acting under hydrostatic pressure will keep up with that pump so mebbe consider planning for more _or_ larger diameter tubes, hence my suggestion you use a weir so you can maximize the current back to the sump from one location. Sorta like increasing the HP on a vaccuum. But there is no need for a weir and the real estate it takes up other than that consideration.


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## cantrell00 (Oct 30, 2010)

Excuse me if this was already asked but is there reasoning for why you can't install on overflow (or two) & run the water through the back glass - down & into the 55 & then return back to the 300? It would be just like any other sump system except it would be behind the tank & not under it. Doesn't really matter as long as the sump is at a lower elevation than the surface level of the 300. to exaggerate the point, the sump could be a mile away & it wouldn't matter as long as it is @ a lower elevation.

Look at glass-holes.com for the overflows they build if drilling is an option. I have used them on two builds & they work very well & are very quiet.

That is the approach that I would take because it is proven to work...


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## cantrell00 (Oct 30, 2010)

Tempered bottom but I don't think they have tempered back panels...

You could call them to verify.. I did on my 180... (back panel was NOT tempered)

http://www.aqueonproducts.com/assets/011/19107.pdf


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## Agridion (Sep 8, 2010)

cantrell00 said:


> Tempered bottom but I don't think they have tempered back panels...
> 
> You could call them to verify.. I did on my 180... (back panel was NOT tempered)
> http://www.aqueonproducts.com/assets/011/19107.pdf


I think Cantrell00 is correct. You could always look at the glass with some polarized glasses like the plastic ones given away at the 3D movies. If you see heat lines then it is tempered. You can test it by looking at the side and back windows on cars (they are tempered).


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## lucid_eye (Apr 12, 2009)

I was not aware of that trick, I have plenty of polarized glasses and have noticed that sometimes windows have the appearance of tempered steal. I will have to check it out when I get home, you learn something new every day. Thanks cantrell


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## taxxara (Dec 3, 2010)

I can see one major flaw in your design atm. 
The siphon is setup the wrong way. A siphon works by pressure difference between the inlet and outlet. Therefore the outlet of the siphon should be lower than the inlet. Therefore in your case water will flow from the 55g to the 300g.

Also the outlet will have to be considerably lower than the inlet, depending on the diameter of the pipe, the bigger the diameter the lower it has to be. I think with 1 foot difference in height a siphon should work but you might need to put it even lower to get the maximum flow out of the pipe you are using.

Now that theory applies, when the outlet is not under water. If the outlet pipe is under water, the difference in height (pressure difference) is between the two water levels. Therefore the water level in the 55g has to be lower than that of the 300g. And not just by a couple of inches, unless you build a really wide spillway as mentioned above..


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