Hydroponic System Syphoning problem

[bowlingo]

Hi all,

I am building a hydroponic system and have an ennoying syphoning issue..

As of the very rough sketch below. This part of the system pumps water from a main reservoir into a small 20 litre container and uses 2 x maxijet 1000 pumps of which have a non return valve on each, go into a Y splitter, flow control valve then off into the 20 litre container using a ball valve. The reson there is 2 pumps is because if one fails the other one will keep working and do the job hence the non return valves to stop the one thats still working pump through the one thats failed.

I have a syphoning issue at the ball valve of the second 20 litre container and it keeps dripping fast when the pumps have turned off. The pumps are controlled by a float switch just below the line of the ball valve as the ball valve is there only for mechanical protection should the float switch fail.

If I pierce the pipe at the top of the main reservoir above the line of the water this sort of does the trick but doing this effects the pressure and also causes a spray.

as you can see in the drawing the pipe goes out the top of the main reservoir, down to floor level then back up and connects to the ball valve

It is only a slow drip I am getting but I need to be able to control this accurately...

anyone any ideas?

I have asked a similar question on here before regarding syphoning but didnt resolve it.

Thanks
Alex

 

[bowlingo]

I have just found this video on youtube of a similar system

http://www.youtube.com/watch?v=d5822dpt7FA&feature=player_embedded#!

At 25 seconds you will see an anti syphon valve any ideas if this is what im looking for?

 

[Weedrip]

Generally speaking if the ballvalve is letting by then the ballvalve is faulty. However in your set up there could be another explanation. If the drip is very small, could it equate to the evapotranspiration of the unit being fed?

How is the receiving tank feed controlled? Is it a simple timer, level switch?

You could use a level switch and solenoid valve [12v would be recommended, I guess]

The level switch would control both pump and valve with the valve then being shut to prevent un-wanted siphon action.

 

[Weedrip]

Meant to post a link for a solenoid valve,
http://www.amazon.co.uk/Hose-Hozelock-fitting-Solenoid-operated/dp/B003W5BGVC/ref=pd_sxp_f_pt

A non electrical anti-siphon valve could also work such as is found in this link, cheap and simple [always a good a ideal]

http://compare.ebay.co.uk/like/350303565004?var=lv&ltyp=AllFixedPriceItemTypes&var=sbar

hope that’s of use.

 

[bowlingo]

Generally speaking if the ballvalve is letting by then the ballvalve is faulty. However in your set up there could be another explanation. If the drip is very small, could it equate to the evapotranspiration of the unit being fed?

How is the receiving tank feed controlled? Is it a simple timer, level switch?

You could use a level switch and solenoid valve [12v would be recommended, I guess]

The level switch would control both pump and valve with the valve then being shut to prevent un-wanted siphon action.

Thanks for your reply...

the ballvalve isnt faulty and its not "evapotranspiration" its definitely a syphoning problem when the pumps turn off

The balvalve is always going to be open as its acting as a mechanical safety device and the pumps turn on and off using a float switch just below the line of the ball valve (see description above)..if something went wrong electrically and it started to over fill the ball valve would stop it.

I dont want to put a solenoid valve in just on the basis of a syphoning issue (expense, more wiring etc)

I am sure there is a way of putting in some kind of anti syphon valve as in the video above at around the 25 second mark.

Thanks

 

[bowlingo]

Meant to post a link for a solenoid valve,
http://www.amazon.co.uk/Hose-Hozelock-fitting-Solenoid-operated/dp/B003W5BGVC/ref=pd_sxp_f_pt

A non electrical anti-siphon valve could also work such as is found in this link, cheap and simple [always a good a ideal]

http://compare.ebay.co.uk/like/350303565004?var=lv&ltyp=AllFixedPriceItemTypes&var=sbar

hope that’s of use.

The anti syphon valve above is a 4mm one for use with car washers...looks like the kind of thing im looking for just a shame its not 1/2"

 

[Weedrip]

You could try a search on hozelock fittings they do a range that will reduce 13mm to 4mm, granted it does depend on what you mean by 1/2" tho.

any real 1/2" anti-syphon valve will cost a fair bit more.

 

[bowlingo]

You could try a search on hozelock fittings they do a range that will reduce 13mm to 4mm, granted it does depend on what you mean by 1/2" tho.

any real 1/2" anti-syphon valve will cost a fair bit more.

this will reduce the flow significantly.....1/2" as in 12/13mm

 

[Weedrip]

it will not reduce flow at all. 13mm / 4mm tee. branch point allows connection of the air break valve.

Untitled

• Weedrip
• 28 Dec 2011
• 1

or cobble up a bottle vent using standard fittings this must however be kept vertical to work correctly.

Untitled

• Weedrip
• 28 Dec 2011
• 1

[/img]

 

[bowlingo]

it will not reduce flow at all. 13mm / 4mm tee. branch point allows connection of the air break valve.

Untitled

• Weedrip
• 28 Dec 2011
• 1

or cobble up a bottle vent using standard fittings this must however be kept vertical to work correctly.

Untitled

• Weedrip
• 28 Dec 2011
• 1

[/img]

do you have a link to that black one?

 

[bowlingo]

anyone any further ideas on this please?