the VanSiphon

Wow great idea!

I bet it's pretty quiet too since the external overflow is completely sealed.

It is pretty much the same as my Life Reef HOB overflow in concept, but obviously the design is different and you save ~$100.

Regarding the over flows failure while you were gone: It could probably be prevented in the future by using a stronger pump (like a dialed back Mag9). I find with HOB overflows you really have to push the limits as to how much flow they can take by using an over sized pump, this prevents air bubbles from building up.

I really think HOB overflows have an undeserved reputation for failure. When they are designed well (like your design) and used properly, they are almost as fool-proof as a drilled tank.

 

Ya im interested in some video too. Looks like a simple project that can be done in a couple hours....awsome

 

looks cool, is it quiet?

 

Thanks for the encouragement! I'll see if I can get a video, it might take me few weeks...I'm not really good at that stuff, plus my active siphon is not in a great spot for video, but I'll give it a shot.

The siphon itself is quiet, it is all enclosed. It gets a bit noisy where the water is going into the bulkhead pipe. And then where it falls into the sump. The siphon level is about halfway down that tube, so the water has to fall 5-7 inches. I don't mind it, the water falling masks the hum of my cheap skimmer:. I've thought about dialing the siphon back with the valve to get that water level up, but haven't tried that long term.

 

sounds pretty good

 

Interestingly enough the siphon failed when the pump went dry...I think either there was an evaporation issue (can't imagine how) or too many microbubbles somehow accumulated. Pump size wasn't an issue then, since the pump ran out of water to pump.

I'm running about 150 gph through this siphon without any problems, in my gardenhose testing I could fill a gallon through the siphon in around 8 seconds which is around 450 gph. It seems to scale very well, provided that the bulkhead is designed properly.

I have made sure that:
a) the tank can handle the extra water in the pump chamber of the sump in case the siphon failed (my old siphon did regularly) and
b) the sump can handle the extra capacity in case the pump fails.

 

That will work - you lose some of the compact design, but then you won't necessarily need to cut down the connectors either since they can be further from the side of the cap.

 

Very cool design. Uses the same principle as the W. What problems did you run into with the W design?

 

I couldn't get it to siphon well. I don't know why. Perhaps it was because I had the pipe terminating underwater in my sump. The only way it ran well was by blocking the air hole, which created a straight siphon, and that defeated the purpose of it since it would lose the siphon if the pump stopped.

Plus I didn't like the way it terminated in the aquarium, with two pipes, and the input up near the top. I suppose I could have created an input the same as the VanSiphon, but I hadn't figured that out yet. It took me a while to figure out why this type of siphon even works this way.:

 

Hah yes it is quite a masterpiece of fluid dynamics. I still am not quite sure what the actual principle is that causes this to work. I am guessing surface tension. The W i use came out perfect on the first build, but I know some people have had trouble depending on the lengths of pvc they use on each side (specifically the dry side)