Backyard Aquaponics
A place to discuss aquaponics

Could experienced APers give me some feedback on the viability of using these to control input to growbeds, I would like about 15 Lpm fill rate fed by fish tank overflow.

http://www.duralirrigation.com.au/onlin ... tionID=737

Think from memory of past discussions.... two issues...

Whether or not solids and the build up of bio-film of time might block them or make them unreliable.... and more importantly .... the pressure needed to operate them... ==> 150 psi

Lots of people are working with gravity drains and can't get near the psi needed to operate them... if you going to try and use them "by fish tank overflow".... then I figure they wont work

I believe they have been tried novaris - there was problems with the pilot orifice being blocked by crud.

Damn you rupe - what happened to the 'someone has posted in the meantime' thingy ?

Many a varied type of these things ,, I've worked in factories that have had cycling ammonia mixed with rusty water running around and the valves often lasted YEARS.
If you get the right type I would say not a problem ( and yes i intend doing the same idea) ..... but definately put a jopiner above and below it for ease of cleaning or replacement if you happened to ge the wrong type.
Your linked ones looked a little expensive ..........
I did a quick hunt and found these http://cgi.ebay.com.au/Irrigation-Solen ... dZViewItem

MAKE SURE , you get the size correct ,, if your only using gravity you will probably need a MUCH bigger pipe than you think ,, I'm aiming at 50 mm minimum.

Exactly RIght Rupe.... not enough pressure. Even my 4,500LPH pump can't open them.

There is a thread somewhere already where people have been working on zero pressure valves. I was also playing around with actuated ball valves.

Do a search for valves...

UHHHH ,, there are valves easily available that simply open on the electric coil being energised ,, they don't care if there is NOTHING behind them. Power / magnetic field/ open.

Sorry, not experienced APer, but

I do have the NETAFIM AQUANET DC LATCHING VALVE ,
http://www.duralirrigation.com.au/onlinestore/index.cfm?NavigationID=642

It needs a short pulse to latch open and a reverse polarity pulse to close,
so it needs a controller, but not difficult to make

tried it but there’s not enough flow, may have use for it later

25 mm , you will get very little flow , especially only under gravity.

I'm chasing minimum 50 mm , but in reality I probably need 75.

All solenoid valves that are commonly found at B for around the $20-40 mark will not open under gravity fed water or via any pressures found from vortex or impeller driven pumps.

At a bare minimum the pressures will slightly open a valve simply using the weight of water on the internal diaphragm (if oriented correctly). However the water
flow will be a trickle at best. Even if you enlarge the port hole and loosen or even ditch the main spring, you can't get much improvement. A large valve like a 50 or 75mm
is a huge waste if you compare them with the alternative...

NOW, a electrically or pneumatically actuated valve will do the trick. These physically operate the valve open and close. However they are very expensive, I am talking well over $100.
But people here have experimented with a variety of cheap alternatives to make a similar device. Like the famous car door actuators and high torque motors attached to valves.

Here is a better question... Why do you need the valves? Do you really need the extra expense? What happens when they fail? Have you considered the alternatives?

AP insomnia
Thanks for the feedback. Given the operating specs of 18 Lpm and 10 psi (0.68 atm) I had hoped they would be ok but SS confirmed the lack of flow with the NETAFIM AQUANET DC LATCHING VALVE it's specifications appear similar. Also with the clogging problem I guess its back to the drawing board

My system eventually aims to have 3 700L growbeds in series from a 500L sump, since each bed will need about 300L I want to run them in series. I am looking at the actuator/flap setup I have seen on the forum and I have another idea I am going to try.

At the moment I am in process of working out how to use sketch-up draw my system. I am part way through construction and will start a thread on it soon

If you want to run solenoids have you thought of useing these[pressure pumps ] dont worry about picking up solids the suction on these will break up any piece of sh=t they you can run irrigation valves $30 bunnings just think of the endless possabilities they auto turn off when theres pressure so just put a timer on the valves ,hi low censers
a sencer to turn of the bed when full then go to the next one

Woops forgot photo

Good point,

Couldn’t find cheep enough suitable solenoid valves so decided to use one small pump for each GB/FT combination in my barrel setup.
Works a bit more expensive but if one pump gives up, it’s only one of six.

I like that Tim

I have been searching for a zero pressure valve for the auto filling of the sump pump to maintain a constant daily water level (ACDWL ), I found this stainless steel one, 20 & 25mm, 0 - 10bar...rang the company and only uses 240vac at that size - price $176 inc GST ( 50mm would be much more costly)

http://www.valvesonline.com.au/products ... series=s35