How to start the overflow.

[gozetec02]

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

The item at that website sparked my interest because it looks interesting and looks very good. My only question is how Would you start a siphon in an overflow like this. I know the idea is to pull all of the air out of the siphon tubes. But lets say the power goes out and I am not there to start the siphon. In the persons pictures of his tank it looks like the airhose to pull the air out of the tank is connected to a powerhead.

Has anyone tried this.

 

[jsoong]

That's a neat concept for an overflow ....

I looked at it carefully & the design is quite good. It mimics a regular double overflow box, so the siphons, once started, will not quit even with a power out. If you notice, the "strainer" inlet tubes regulate how low the water can be inside the overflow system, and that level is never lower than the inlets & the outlets of the siphons. Therefore, the siphon will not empty even with a power out. This is the same principle that keep a conventional overfow box siphon primed during a powerout.

I am having trouble visualizing the initial priming of the siphons, however. I would assume that one would snake an airline into the siphon & suck the air out. But with the bends before the siphons, that would be a bit difficult .... although you would only have to do that once ......

One other thought on that setup. It has 2 siphons, but they appear to be connected. That would ease the initial priming, but with a connection, if you lose suction in one siphon, you lose it in the other too. I am a bit paranoid over siphons quiting. I have 2 siphons, but they are not connected & both work independently. So if one quits, I still have the other one.... a double redundent safety factor .... But then I also have 2 hoses & distributor pipes leading to the wetdry, just in case one gets plug up ..... may be I just worry too much!

 

[gozetec02]

I think its a great idea. From the look of his aquarium it looks very effective. Also because the pvc blocks any light you would not have to worry about algea cloging up the works. I will build it this weekend and report on its function. It looks promising. He also drew it in a program called AutoCAD which i work with every day and there is a 3D drawing that i can open and spin and rotate to my hearts desire and even build it to scale.

 

[fishfreek]

The way I see the syphon being started and maintaned is this.

On the graphic there is a 45* elbow that is the hightest most point on the overflow. This is where air will collect if there is any. If you put a hole at the top of this elbow and affix a small hose fitting. 1/4" ID. Then either attach a very good closing air valve to the hose or run the hose into a PH's venturi hole. If you pull air out of the overflow when its installed via this line then you will effectivly prime the overflow. If you close the airvalve and the seal is nice and tight the overflow ill never lose its syphon until air can somehow find its way into the system. If you attach a PH to the hose via the venturi then the operation of the PH will pull the air out and keep any new air out of the system. Should for some reason the sypon fail as long as the PH is running the syphon would be started up again as air was vacated from the overflow.

 

[guitarded]

well, i think at all the questions about how the siphon is started is probably best answered by the individual who created it. so i emailed him and asked. i will let you folks know what he says if he replies.

 

[gozetec02]

I have emailed him a few times with no replies.

 

[guitarded]

ah, so we are back to square one!

 

[jsoong]

I am planning to redo my overflow so been thinking about this a bit.

I wonder, if you submerge the whole thing & slowly rotate it 360 degree, that would get rid of all the air. Then, lifting it out of the water right way up should keep the siphons primed & ready....?

If someone made one of these, I would like to know if this method actually works.

 

[Sandworm]

jsoong, I was wondering that same thing.

 

[easyian]

If you look at this pic http://www.nd.edu/~lego/grp2/www/reef/psn00024.jpg you can see a hole just below the waterline on the left siphon tube to break the siphon in case you need to.

 

[easyian]

Ok so I built this thing and so far so good. I figured out how you start it. You just have to turn off the drains below the overflow and fill the opening left in the middle at the top. I havn't been able to test it out yet as I don't have a return pump for the sump and I have to build my refugium first so in the next couple of weeks it will get done and can post some pics then but first i'll leave you with this.

 

[guitarded]

what size pvc are you using?

 

[guitarded]

ok, i see on the originator's site that it is 1" pvc. i would be interested in its gph rating.

 

[gozetec02]

Are you planning on adding the strainers like they show on the website. I was thinking instead of cutting slits in the PVC you could drill a bunch of holes and this would serve the same purpose.

I am planning on bulding a Sump/Refugium soon and will use this type of overflow to get water into the sump.

I am glad to see that i sparked some DIY interest.

 

[BillyZ]

deffinetly post up some GPH numbers when you get the opportunity to test.

see how long it takes to fill a 5 gallon bucket and calculate from there.

 

[easyian]

Starting it is harder than I first thought. When I had posted last I had just done a quick tryout in the laundry tub. I was working but not 100%. I hadn't gotten all the air out of the siphon tubes. I had to twist it around in the tub to get the air our so it would work properly. So my solution is that I'm going to put a small drain cock at the top of the crossover in the siphon tubes so I can suck out the air. Hopefully this works.

I don't have a clue how I would figure out the max GPH. it kept up with the tap in the laundry tub but that is only 60 gph I believe. It is very large. I used 1" PVC . I guess as long as it keeps up with the pump I add to it iamb ok. I was thinking the little giant 4mdqx-SC it claims 1350 gph at 0 head and 900 gph at 5 ft head. I have about 3.5ft head so iamb guessing about 1100 gph on a 90gal tank would suffice. Also gonna add a scwd.

 

[easyian]

Did it really beep out the proper name for an item? At first i was like what did I write that was beeped out. Anyways I added the drain "thingy"(shut off valve) to the top of the siphon tube and is now a breeze to get started the only thing is its kinda ugly but the canopy will hide it. Hope fully I will get my pump in the middle of the month and then we're off to the races.

 

[guitarded]

what kind of flow will you be looking for?

 

[easyian]

Hopefully about 1100 gph.

 

[guitarded]

please let us know how it works out for you when its operational and if it is providing enough flow.

oh, btw, thanks for being the "test bed" and sharing the information with us.