Runnign skimmer with siphon

[Neopimp]

Is it possible to run a venturi type skimmer with the down flow of a 1.5in full siphon dropping 15 ft?  Instead of using a pump I mean? I have not looked too closely at skimmers so forgive m if this is just a stupid question. I was reading that some 1 inch full siphons can pull anywhere from 900 to 2000... again I have no idea how accurate it is but that kind of flow is more than some pumps are putting out to the skimmer.

 

[Blob-79]

hm..gonna have to research that one....1.5" full syphon? seriously? thats HUGE flow

 

[Neopimp]

ya its my brothers tank... think it is 1.5 or 1.25 ... he bought an EV240 and it says it needs a pump for 1800 gph.  IF the skimmer works on the velocity of water flowing through the venturi, would the full siphon be fast enough to suck the needed air.  Again I haven;t even looked at skimmers too closely yet so oi may be a stupid question

 

[pulpfiction1]

i dont know about your skimmer but the one i use(MRC 2) needs 1100 GPH with beckett downdraft,it needs the pressure as well as the flow rate to inject enough air,i use a blueline pressure pump on it

i did a quick look at the manual on it
c/p:
the EV-240 performs best when powered
by a pressure-rated pump capable of producing 1200-1800 GPH unrestricted. Due to
the pressure that the spray injector places on the pump, the true flow through the
skimmer will be quite a bit less than the unrestricted rating.

link to the manual:
http://www.proteinskimmer.com/User's%20Manuals/EV-240.pdf

 

[pulpfiction1]

there was someone selling a mag18 pump at a decent price a while back,search it out,might still be availanle

 

[Blob-79]

Im working on the dynamics of it. But I have a couple questions. This 1.5" full syphon, does it have a valve to regulate flow (ie. beananimal type overflow) or is it full blown open syphon..im assuming its regulated with a valve...cause 1.5" is HUGE flow with a full syphon. If it is regulated where is the valve located for regulation..behind the tank, or downstairs by the sump. Would he be able to run another full unrestricted smaller diameter tube down? If he can im pretty optimistic that it is possible. without doing all the actual calculations, I know just a 1 1/2"pipe in full syphon will move about 4750 gph with around 7 lbs pressure not accounting for flow velocity or anything,at the head height you specified.(this is why im kinda skeptical about it being a full unrestricted syphon)

Let me know the details and I can run the numbers for you. or advise what will need to be changed.

 

[Neopimp]

ya there is a valve.. behind the tank i think... It is most definitely restricted some, well probably more
Being the kind of guy he is I am sure he is going to try it whenever it gets here.
I was just asking out of curiousity
I will let you guys know the outcome

 

[Neopimp]

He tried.. not enough pressure behind it I guess. Oh well it was a nice thought

 

[Blob-79]

you should tell him to try it with the restriction valve down by the skimmer instead. he may need to add about 1.5 gallons of water..depending on his water level in the sump. open the upstairs all the way, then open the valve downstairs untill the water is raging . Then just close off the valve in the basement untill hes getting the flow he wants. basically to get the air out. then you will have water pressure at the skimmer.

 

[Noodle]

I wouldn't recommend it.  Your skimmer is your most important piece of equipment.  If you have a sump, put the skimmer in the sump and give it a real pump or needle wheel internal pump.  Don't try and hack a skimmer into a plan.

 

[Neopimp]

Call it more an experiment
He said it worked a bit but not near what it shoulda been so he went and got the mag18 for it. 
Pulling junk out now

I will suggest he give that a try Thanks