# DIY HOB overflow/sump/filter who wants to see it?



## kshah (Aug 24, 2010)

I was just thinking about sumps last night, so I'd appreciate a writeup or parts list and some more detailed pictures. Your system looks simple and compact enough that I'd try my hand at making it. I've got a 25 tall planted tank that could use some extra filtration. 

Do you have a HOB filter running simultaneously or just the sump?


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## VaultBoy (Nov 11, 2010)

O.K. here we go... i took a heap of photos today when i took it apart to clean it. this whole tank/sump setup has been built on a super tight budget, this sump/filter cost less than $50 to build but i had a lot of parts to begin with so if didnt have these parts it would have cost significantly more.

kshah: i run an in tank power filter also this is mostly for flow in the tank but it does a lot of mechanical filtration also.

I did not want to drill the tank so i had to work out how to run a HOB overflow and after a heap of reading i found plans to build a very simple constant siphon overflow out of P.V.C. pipe. It took me a while to get my head around the concept of a siphon overflow that wont flood my house if the power shuts off but this does the trick.

















Here the plumbing from the overflow enters the bottom of the cabinet and enters the lid of the bucket








I didnt glue this joint for ease of maintenance, i was worried about leaks but it hasnt been a problem yet









Here you can see the tube that runs into the top of the filter and spreads the flow through the filter floss in the top.









This is just a salad bowl with a bunch of 1/8 inch holes drilled though it, its normally filled with a heap of filter floss but i had a friend who need to jump start a tank for his turtles so he got all of the media filled with billions upon billions of little bacteria to help him 









This is the bucket with as many body scrubbers as i could fit in and a bag of carbon for good measure. I couldnt get a pic of the bottom of the bucket, i kinda built the stand around the sump and it doesnt fit out, but if you use your imagination and picture a bucket with a heap of holes drilled in the bottom you will be pretty close.









The sump itself is approx 16g tank (24" long, 12" wide, 16" tall) which i had laying around. It holds about 10g when the pump is running and when the power stops the main tank drains down a bit and fills the sump, so no flooding. The pump is nothing special i bought it from a local hardware store, its sold as a water feature pump, and pumps about 100gph at this head, which doesnt seem like much but it does a great job of cleaning the water.

The pump returns the water to the tank via a spraybar that i build out of some flexible clear P.V.C tubing, and the cycle starts all over again.

There you have it, a simple cheap DIY sump and filter that almost anyone could build themselves.


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## bobalston (Nov 8, 2003)

Can you post more info on your overflow box?

Bob


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## Kathyy (Feb 22, 2010)

Great stuff, gave me lots of ideas on how to change my sump around. My sump currently just has a large sponge in it with very little mechanical filtration.


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## VaultBoy (Nov 11, 2010)

Here is a diagram that might shed a little light on the overflow setup.

The water flows through the siphon pipe into the "u" shaped area, this will hold water constantly and the siphon wont break until i drain the tank down past the inlet of the siphon. When the water level in the tank raises above the overflow outlet the siphon kicks in and allows water to flow over the top and out the outlet into the sump.










The pipe on the left is the air break it has a small hole drilled in the top of the elbow and the tube is just there to keep the noise down, without it, it would make a gurgling noise.

The pipe on the right is the constant siphon, it has an airline stop valve fitted into the top for priming the siphon (just hook up an airline and suck the air out)










This is all made with 3/4 inch P.V.C. pipe i should have used 1 inch but this is what i had laying around so it cost me nothing, the bigger the pipe you use the more flow it will handle. This is just a simplified version of a commercially available overflow box, works just the same exccept the "u" pipe is the box.

I hope this makes more sense... it took me ages to figure this out 

The only thing i plan on changing is adding another overflow just for peice of mind, because i have had a close call with this one when a heap of leaves blocked the siphon tube, becuase i have a mesh screen on it. If i change the mesh screen to a prefilter sponge i dont think it will happen again.


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## Hoppy (Dec 24, 2005)

Make the change in purple and it can never overflow the sump. The flow from the tank stops at a specific water height in the tank. I have a couple made this way for a different use, and they work great.


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## VaultBoy (Nov 11, 2010)

when the level in the tank drops below the overflow outlet it stops draining. the only way this can ever overflow is if the inlet to the siphon tube gets blocked, and the pump keeps pumping, it will overflow the main tank not the sump.

I have a 1g betta tank that will one day be repurposed as a surface skimmer/overflow weir which will have the same effect as the modification that you mentioned.


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## Vonzorfox (Nov 22, 2007)

Nice work. I might give this one a go with 1" pipe on my 75g. I'll use a 20g for the sump instead. Is there a specific length for the inlet with the screen on it? I understand the longer u shaped one is so the water level will not drop below that in case of a power failure.


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## VaultBoy (Nov 11, 2010)

The inlet pipe with the screen on it can be set to any depth you want or even incorporated into a surface skimmer like hoppy's pic shows. The level of water in the tank is governed by the height of the overflow outlet which is the "T" piece. The level in the tank can be adjusted by moving the whole assembly up or down.

Here i made another diagram that hopefully explains it a bit better. This is the same as the diagram that i was working from when i made mine, the concept is the same but the execution slightly different. As the water level in the main tank rises the siphon tube begins to flow into the overflow box to equalize the level and then flows out of the overflow outlet and into the sump.










The "U" shaped pipe is the overflow box, the pipe on the right hand side with the screen fitted is the siphon tube, the "T" piece on the left is the 
overflow outlet. The detached piece is just used to silence the noise from the overflow box it has a hole in the top about 1/4" diameter and the end of the tube sits below the water level in the tank.










Hope that helps. Just let me know if you need any more help understanding it, it took me ages to figure out the concept then about 30 mins to build it.


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## VaultBoy (Nov 11, 2010)

I edited the diagram a little to look a little bit closer to the one I built, the concept remains the same.

I also added (in purple) a completely optional way to incorporate a surface skimmer (I have not done this and dont really see the need to, maybe in the future when i get bored and run out of projects)


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## Vonzorfox (Nov 22, 2007)

Ahhh, I see light. Thanks for the easy to understand concept. Eventually when I'm ready to replace my canisters I'm going this way, no drilling and no fuss. Excellent info.


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## [email protected] (Apr 27, 2011)

Ty so much Vaultboy, will def. b building this and adding it 2 my tanks. Will probably also use the mod Hoppy suggests 4 insurance purposes, 2 insure my wife will let me continue with this hobby after not flooding her house:icon_smil

Was thinking that Hoppy's mod was a lil overkill as I was reviewing your post again, for about the 20th time cuz of the excitement over the build. It was then that I realized, "the u in the pipe was the overflow".  I also thought about getting 1 of them big round filters 2 go over the outlet 2 the fuge 2 take care of any stray debri b4 it clogs.

Was thinking about the pump continuing 2 run n overflowing the MT. If u were using a submersible pump into your MT u could simply mount it higher. When the water level in the fuge gets 2 low it will no longer pump. Mine even came with lil suction cups so I can pretty much mount it anywhere. Might burn your pump out if on 2 long but i would rather replace it than have 2 clean up 60-75g of water.


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## [email protected] (Apr 27, 2011)

Vaultboy, could u take a couple pics of your canister filter and the position of it and also the pump u r using back 2 your mt and where it is located? Thank u very much, can't wait 2 build this. Have most of the parts as u did so it shouldn't b that expensive or complicated 2 set this up. Will post pics of it as soon as it gets done.


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## VaultBoy (Nov 11, 2010)

The first pic right at the top of the page shows the bucket full of shower scrubbers in the sump that is the filter it is literally a bucket with holes drilled in the bottom full of body scrubbers. The pump is just a cheap fountain pump from the local hardware store and I put it in a small plastic jar with some filter sponge stuffed in it to stop the fry in the tank from getting sucked in.

Any other pics you want speciffically i will take when i pulle the tank down soon to convert it to a reef tank.


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## SlammedDC2 (Jun 4, 2011)

I'm definitely interested in more pics, I think I'm going to do about the same thing in my 125g


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## matty26 (Feb 25, 2011)

questions: 
In you pictures you have 2 pipes going into the tank. Is that just for more flow? do you have to line up the overflow outlet with the waterline or can it be anywhere below it? How loud is this overflow, noticeable noise? does it matter how tall your pipe with the open top is?


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## [email protected] (Apr 27, 2011)

Getting ready to use the info here for my 9-tank rack I'm constructing, so figured I would bump it up so that others can read the great info included here as well.


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## Wicket_lfe (Aug 21, 2008)

that "Silencer" makes me nervous. lol


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## silvawispa (Oct 11, 2011)

Had a bit of a think about this, and about Bean Animal's silent fix.
Here's my thoughts graphically represented...
Comments and criticisms please.


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## [email protected] (Apr 27, 2011)

Would most definitely be interested in any test results and/or findings brought on by your assembly and tests. For me, I'm not so worried about sound/silence. The rack I am going to be using this for is going into an unused closet in the spare bedroom, at the other end of the house. My 105g is in the livingroom, and I hear that as the water runs over the overflow, down the drain, and into the sump. I will probably never hear it from there, no matter how loud it is This definitely looks like it would be interesting to put together and test. Good luck, and please post your results for us? LOTS of us on here do DIY because we love it:hihi:
Also, didn't know what a venturi intake was either. Now I'm on a mission to get a new pump:biggrin:


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## Svynx (Nov 8, 2010)

silvawispa: glad to see someone else is familiar with BeanAnimal. I used his 3 pipe drain system on my 40 breeder.


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## tentacles (Nov 28, 2011)

I've made a bunch of overflows out of those little fish isolation boxes, glued together, with a U made of 1.5" PVC between them and a 1.5" drain with a 1.25" hose barb for that corrugated sump pump tubing (*MUCH* quieter with this stuff... no gurgling). You really don't even need to glue them together, you could just offset them at the back and make the "U" to fit. 

These kind of boxes is what I'm talking about: 










Simply cut down the inside box to match your desired water level - hack some off or cut slots, whatever you like. They are not the toughest setup, but mine held up really well. 

For even quieter operation put a piece of very coarse open cell sponge on top of the drain, but this doesn't work well with higher flow setups.


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