diy overflow

[]v[onster Loaches]

Not to take away from the original design from the OP but I was curious if anyone has ever built and used any of these DIY PVC overflows that are based of the same princibles but different configuration:

http://www.nd.edu/~lego/grp2/www/reef_diy.htm

3 intakes, 2 drains, and would need only one check valve (or however you choose to remove air).

and

http://reefcentral.com/forums/showthread.php?threadid=503664&perpage=25&pagenumber=1

The 'pretzel'. Two intakes, 1 drain, needs two check valves. Just a note, reading some of the responses on that last one (on reefcentral) was rather halarious when people had no clue how it works or what it was even for lol.

On my current project I decided to go drilled, so I have yet to build a DIY one but I think in the future unless I drill the tank myself I am going to do a PVC one, and curious what you all who have done this think of these alternative designs.

 

[stardotstar]

In my opinion the biggest issue once the power failure/intake blockage problems are handled is the aesthetic of the thing. The first one I built would be very hard to disguise and because of the way I designed the outlet for the sump I had very little flexibility with the location of it in the tank. Because of lid rails on the back and sides of my tank it would not sit flush with the back glass and due to using drainage PVC fittings it leaned out into the tank (elbows in drainage are 85°) and even pained black would have been pretty ugly.

My current design should help with all this since I have the Fluval intake and return, the heater, airlines and an otto in the two back corners anyway, so I will be putting all the hardware together and the main expanse of the back wall will be undisturbed with the bottom of the main loop under the substrate.

I can't seem to find Krylon Fusion in Australia (unless I buy a whole case!) so I am considering running with the unpainted pvc initially and spending time ensuring that the level in the sump and tank are matched so that a blockage will not flood from the main tank when the sump is drained by the pump or in the case of a power outage the sump can accommodate the drop in waterlevel to the bottom of the invert in the main tank.

I will post some pics when its installed.

The links you posted were impressive designs but I feel that they are too bulky for my 5' tank and although they could be re-configured to fit just about anywhere the design here by Chompers et al is effective, simple, cheap and easy to disguise.

 

[stardotstar]

Here are the bits I used:

and here is the contraption curing

The sump is nearly finished - just got to do the drip tray and then see if I can fit this piping in in one piece (should be ok - but the angle I have to use with the bracing on the tank means that the roof might get in the way!)

Will

 

[]v[onster Loaches]

This does look pretty nice! But what is the particular reason for doing it this way? You have the same amount of vertical pieces in view, just on both sides now instead of 1 (I'd think having them together would actually be easier to hide with driftwood, moss, etc) and now you also have 4' or whatever the length of horizontal piece is. This might make it very hard to remove unless there is some kind of union which would further diminish the aesthetics in the tank. And the long horizontal run might reduce flow somewhat (might not really be a problem so long as you still get enough flow) but also increases the chance of gunk building up, etc. Anything that gets sucked in might settle out in the long horizontal section. But so far it does look first class!

And some questions I had about your earlier post:

Yes Chompers, that means that the flow could only be increased by raising the height above the tank of the top loop - which in most cases would be unsightly and impractical. Oh for a fish room behind the tank

I wouldnt think that increasing the height of the top loop or lowering the bottom loop would help. Mind you I have not built one of these so if I am wrong please correct. And Chompers said:

The maximum flow is determined by the maximum distance between height of the top loop and the placement of the tee. As long as the tee is above the inside loop, you will be ok. However, my brain is still asleep so I didn't review the flow through the pipes. I think you understand it well enough though.

Shouldnt it read instead The maximum flow is determined by the maximum distance between height of the water level in the tank and the placement of the tee? I dont really know just by looking at it thats what I would think. The loop height over the tank is a siphon with water going up and down so any increase you make will increase both the rise and the fall which should cancel out, except its going through more pipe with a little more loss. For example you couldnt expect more flow if this were 20 foot tall would you? If this is true then the same should be true for the bottom loop, any extra fall is balanced by extra rise on the other side. I'd think having the top loop resting on the tank glass and the bottom loop right at the tank base would be best?

 

[stardotstar]

Well the T has to be above the inside loop for the system to hold prime when the pump stops and the reason I have made it that way is that instead of a U bend taking up a large amount of space in one place I simply have one stand pipe in each corner.

It actually looks really good and I am very happy with the result.

I'll post a photo later.

 

[stardotstar]

Here it is.

The elbow (which I have yet to put a grill on) has silenced things considerably.

The presentation of the aquarium is excellent imho compared to the previous unit sitting on the back wall - but then again I had to mount that one 1/3 of the way from the left side of the tank so it was always going to look obvious - and furthermore because I made it of drainage instead of pressure pvc it angled out into the tank. This one sits perfectly on the back of the tank and the flow rate is large and quiet. I have an aqua one 2400lph pump wide open with about 1.2m of head.

I know I have a lot of ugly gear on the back wall corners so the pipes do not bother me too much now that they are well back and to the side. Also the white colour means that they light the tank from the sides which actually looks quite good.

Cheers for now.

 

[craigthor]

How big of a difference does having the tee at the bottom of the vent or in the middle make? My overflow is barely keeping up with my Queit One 2200 ~400 GPH at my head height. My tee is ~6-7" or close to the middle of my vent.

Craig

 

[]v[onster Loaches]

Craig - thats been asked and answered many times on this thread. The short of it is the higher the T the less the maximum flow will be. So if your overflow is struggling to keep up that could very well be the issue. Unless your limited somehow (like in coolkieths design), I'd always but the T up against the bottom elbow piece so it is as low as can be.

 

[craigthor]

Craig - thats been asked and answered many times on this thread. The short of it is the higher the T the less the maximum flow will be. So if your overflow is struggling to keep up that could very well be the issue. Unless your limited somehow (like in coolkieths design), I'd always but the T up against the bottom elbow piece so it is as low as can be.

Yeah after rereading the thread that is what I got, I'm also going to bump it up to 1 1/4" PVC also. Should be interesting.

Craig

 

[arkmann]

I read through the whole thread before but I guess I'm lazy to look. What sized PVC should I use for an overflow for a 100G tank? What size would be ideal?

I know I still need to do research on the GPH ratings and all that...