Hot Tub Forum

Original => Hot Tub Forum => Topic started by: drewstar on April 03, 2006, 02:06:09 pm

Title: Siphon trick or foolish user?
Post by: drewstar on April 03, 2006, 02:06:09 pm
Well I had a productive weekend.  Part of the "honey-do" list included a water change out.  (4 months of the old water. It held up well, IMHO).

I decided to give the "super Siphon" trick a try but I had no luck.

I used a 10' leanght of pool vac hose (1 1/2 -2" dia) and tried to get a siphon going by holding one end up to a jet on high.

I had no luck!  ???  I've done this on my pool with a garden hose, is the vac hose too large?  

finally I ended up using the drain plugs and my 1/2 hp quick pump.  
Title: Re: Siphon trick or foolish user?
Post by: Tatooed_Lady on April 03, 2006, 02:14:06 pm
maybe the 10' wasn't enough length to keep things moving through that hose?
Title: Re: Siphon trick or foolish user?
Post by: drewstar on April 03, 2006, 03:06:22 pm
Quote
maybe the 10' wasn't enough length to keep things moving through that hose?




I originaly would think a shorter run of house would be easier?  But then again, a longer leagth, once the water is flowing would create an appropriate vacuum. No?

I am thinking the vac hose, at 2" dia was a bit too  large. I'm thinkning yea, either longer hose at this dia or a smaller dia at this leagth?  Can anyone confirm my half assed sceince?  What's the largest sized hose that others have used successfully?
Title: Re: Siphon trick or foolish user?
Post by: wmccall on April 03, 2006, 03:10:06 pm
Does your spa inject air into the water?  I've not tried this technique yet, but if I did, I would turn off the air injection thinking it might break the siphon.
Title: Re: Siphon trick or foolish user?
Post by: drewstar on April 03, 2006, 03:11:07 pm
Quote
Does your spa inject air into the water?  I've not tried this technique yet, but if I did, I would turn off the air injection thinking it might break the siphon.



Nope. No air.
Title: Re: Siphon trick or foolish user?
Post by: Drewski on April 03, 2006, 03:16:52 pm
Hey Bud:

For a siphon to work correctly the suction end must be higher than the drain end AND the hose must support vacuum pressure. The higher it is, the better the flow.

I use a wet-vac to help with this process. I connect 2 wet-vac hoses with an adapter, plug the end into my wet vac, have my kid hold the suction end in the bottom of the tub and turn the vac on. When water hits the vac I pull the hose out and put it under my foot. I have a 6 HP Home Depot “Rigid” vac, so it REALLY sucks! Generally, in about 15 minutes, my 500 GAL tub is almost empty. Sometimes I lose suction toward the end, but can regain it if I'm careful. I also use the wet vac to suck out the remaining water and blow out the heater water and water in the plumbing using the vac in reverse.

Been doing this for 2+ years now and it works GOOD, usually no more than 30 minutes from beginning to end...

Drewski

8)
Title: Re: Siphon trick or foolish user?
Post by: Zep on April 03, 2006, 03:18:48 pm
(http://pics.ebaystatic.com/aw/pics/logos/logoEbay_150x70.gif)
(http://images.channeladvisor.com/Sell/SSProfiles/20059133/Images/subpumpn.jpg)

1/2 HORSEPOWER SUBMERSIBLE WATER PUMP
This 1/2-horsepower submersible pumps up to 2000 gallons per hour and makes a great sump pump.

Current bid: US $33.99


Title: Re: Siphon trick or foolish user?
Post by: drewstar on April 03, 2006, 03:34:19 pm
Drewski....Hmmm.  Maybe I'll try my wet vac next time.   The hose was higher than at the drain side.  


Zep, 2000 gallons per hour?  :o

Damn!

I have this, it's 1/2 hp and rated for about 600 gph.  Cost? $150.  (Yes Bonie,  it's a CRAFTSMAN. :) )

Why is one 1/2 horse pump dumping 3x the water than the other, and apperently significanlty less money?    

(http://img112.imageshack.us/img112/8033/pump9ws.jpg)
Title: Re: Siphon trick or foolish user?
Post by: Snyper on April 03, 2006, 03:50:58 pm
Quote
(http://pics.ebaystatic.com/aw/pics/logos/logoEbay_150x70.gif)
(http://images.channeladvisor.com/Sell/SSProfiles/20059133/Images/subpumpn.jpg)

1/2 HORSEPOWER SUBMERSIBLE WATER PUMP
This 1/2-horsepower submersible pumps up to 2000 gallons per hour and makes a great sump pump.

Current bid: US $33.99





I have one exactly like that, got it from eBay, perhaps the same guy. Works like a dream. I can drain my spa in less than 10 minutes.
Title: Re: Siphon trick or foolish user?
Post by: anne on April 03, 2006, 04:04:40 pm
Quote

I used a 10' leanght of pool vac hose (1 1/2 -2" dia) and tried to get a siphon going by holding one end up to a jet on high.

 


The hose is rigid, right? Otherwise no vaccuum.

Also, the larger the diameter of the tube, the more "flow" you'd have to create from the jet to get the syphon started. Maybe the jet is not "strong" enough for that hose. Try a bigger (higher volume, not pressure) jet? I dont know at what point the length of the hose affects the vaccuum created, but I do know that you need more volume water per second for a larger diameter hose to create a syphon.  
Title: Re: Siphon trick or foolish user?
Post by: drewstar on April 03, 2006, 04:11:06 pm
Quote

The hose is rigid, right? Otherwise no vaccuum.

Also, the larger the diameter of the tube, the more "flow" you'd have to create from the jet to get the syphon started. Maybe the jet is not "strong" enough for that hose. Try a bigger (higher volume, not pressure) jet? I dont know at what point the length of the hose affects the vaccuum created, but I do know that you need more volume water per second for a larger diameter hose to create a syphon.  



I think you are right about the pressue. I'm not following you on the hose ridgidness.  hwo would that affect the vacuum?


hey....if  my hose is rigid or soft is between me and Mrs Drewstar.  
 ::)
Title: Re: Siphon trick or foolish user?
Post by: anne on April 03, 2006, 05:10:16 pm
Quote


I think you are right about the pressue. I'm not following you on the hose ridgidness.  hwo would that affect the vacuum?


hey....if  my hose is rigid or soft is between me and Mrs Drewstar.  
  ::)



Whoa, not trying to get personal, just trying to help! I'm sure your hose is rigid enough to do the job ;)

As far as emptying a tub (that was the topic, right?) I just meant that the hose has to hold its shape- like a garden hose compared to a firemans hose.  His water hose! ;D If the hose is too soft, it'll collapse with the negative pressure created bythe vaccuum, and the bigger the diameter of the hose, the more likely that is to be a problem. I should have said "thick walled" rather than "rigid".
Title: Re: Siphon trick or foolish user?
Post by: dirtrubber on April 03, 2006, 06:22:20 pm
http://www.harborfreightusa.com/usa/itemdisplay/displayItem.do?itemid=45019   I have one from here works great a little cheaper
Title: Re: Siphon trick or foolish user?
Post by: jsimo7 on April 03, 2006, 11:47:08 pm
On my last water change I used a 1 1/4 cheap pool hose 25' lenth put it all in the tub and filled it with the jets in the water. I put a pair of vice grips on the end to hold it at the bottom and held my hand over the other end and pulled that end out and it started running and drinned in about 30-40 min. My tub sits about 1 foot above where I could get the lower end of the hose
Title: Re: Siphon trick or foolish user?
Post by: Brewman on April 04, 2006, 08:27:04 am
As mentioned earlier, a siphon works only when the discharge end of the hose is lower than the input end.  
And the farther below, the better the flow.  
Air entering the hose anywhere along it's length will cause the flow to slow down or even stop.  
I've started thousands of siphons, it's very common in brewing.  After a while you just develop a knack.

It will be trickier to get a 2" siphon flowing than a garden hose.  More area to deal with.   You need to make sure the hose is almost full of water.  Try dunking the entire hose in the spa, until bubbles stop coming out, keep one end in the water, move the other end to where you want, making sure the water doesn't all pour out and let go once the far end is lower than the spa end.  If done properly, it has to work.  
The jet pump method will work too, as long as enough water is pumping through the hose.  



Title: Re: Siphon trick or foolish user?
Post by: drewstar on April 04, 2006, 09:02:39 am
The hose I used was not a thin collapseable
Backwash hose, it was fairly ridgid.   I  did submerge the hose completely and removed any air from the hose. I think I just wasn't able to get enough flow going though the hose to create the vacumm/draw needed for a siphon.  A smaller diamerter hose would be easier, but perhaps I can find a jet that has more head pressure might also do the trick.
Title: Re: Siphon trick or foolish user?
Post by: Brewman on April 04, 2006, 11:57:16 am
Yeah, I think you're onto the solution.  
The larger diameter of the hose is your challenge.  
But once that water starts, whooshhh......
You'll drain very quickly.  
Title: Re: Siphon trick or foolish user?
Post by: drewstar on April 04, 2006, 12:05:37 pm
Quote
Yeah, I think you're onto the solution.  
 The larger diameter of the hose is your challenge.  
But once that water starts, whooshhh......
You'll drain very quickly.  



I think so too. but this thread has brought up another point that confounds me.

Pumps.

I thought pumps were all about HP (Brake and continuous)

Here in this thread, we see a 1/2 hp sump pump moving 2000 gal an hour, and my overpriced Craftsman 1/2 hp only moving 600 gph.  What would be the diifference ? Shaft size? Impellor?  
Title: Re: Siphon trick or foolish user?
Post by: Bonibelle on April 04, 2006, 12:14:41 pm
Must be Sears deceptive marketing  ;D ;D ;D

Just kidding Drew.....
Title: Re: Siphon trick or foolish user?
Post by: drewstar on April 04, 2006, 12:23:10 pm
Quote
Must be Sears deceptive marketing  ;D ;D ;D

Just kidding Drew.....



Damn you Bonnie,  ;D  Don't you have a mower to go and buy?  ;)

The 600 gph seems right based on my use (pool and spa use).   I wonder if the sump pump is indeed 2000 gal.   They are both 110v units...same HP, but one is moving 3x the water....wtf?  ???
Title: Re: Siphon trick or foolish user?
Post by: tonyp on April 04, 2006, 12:44:40 pm
I use a pool hose.  I keep the hose above the spa and slowly submerse it with the end in the spa weighted down.   After the whole hose is in the spa I put my hand over the end and quickly pull it out and drop it along side the spa so that it is lower than the end in the spa.    I then arrange the hose to drain when I want the water to go.  

Actually easier than using a jet.  It just takes practice.
Title: Re: Siphon trick or foolish user?
Post by: Bonibelle on April 04, 2006, 01:57:41 pm
Drew I don't know anything about how horse power actually relates to the volume of water it can move, but I do know that when I buy pumps for my fish pond, (and sometimes I move to a bigger pump every few years) I just look for the GPM rating.
Title: Re: Siphon trick or foolish user?
Post by: drewstar on April 04, 2006, 02:09:36 pm
Quote
Drew I don't know anything about how horse power actually relates to the volume of water it can move, but I do know that when I buy pumps for my fish pond, (and sometimes I move to a bigger pump every few years) I just look for the GPH rating.


It's got to be intake/discharge that dictates gph.  I was hopping one of the techies would educate me, but it's quiet in here today.
Title: Re: Siphon trick or foolish user?
Post by: hymbaw on April 04, 2006, 03:14:32 pm
Quote
Here in this thread, we see a 1/2 hp sump pump moving 2000 gal an hour, and my overpriced Craftsman 1/2 hp only moving 600 gph.  What would be the diifference ? Shaft size? Impellor?  


I believe the HP ratings are for the electric motor.The motor only spins the pump.

GPM would depend on the pump itself  a.k.a. the wet end

That's why HP is misleading. Go by GPM.
Title: Re: Siphon trick or foolish user?
Post by: drewstar on April 04, 2006, 03:34:29 pm
Quote

I believe the HP ratings are for the electric motor.The motor only spins the pump.

GPM would depend on the pump itself  a.k.a. the wet end

That's why HP is misleading. Go by GPM.



Got it.