ello


I'm building a fiarly simply gravity fed automatic watering system for my next grow. I've picked up one of these: (link removed) - standard hosepipe water timer thingy


however on reading the instructions it requires a min pressure of 1 bar, so unlikely to work in my gravity fed system. Just wondering if anyone has any ideas for an alternative. I think if I could find a simple electronic water valve I could cobble something together using a timer to switch it on/off but googling for such items turns up mostly washing machine valves which are probably going to be more complex than I require.

anyone care to throw some ideas at me? all mad prof. style concepts welcomed

thanks

a washing machine valve would probably be spot on for it, i'm sure i've seen 'em used here before.

as long as you're competent enough to safely wire it up , i'd use a digital timer for accuracy and bob your mothers brother

ED:don't know if back EMF from one would trip an RCD though

p.s. have you read the rules about not putting up links

you could save the pic (resize it a bit if needed ) and description, load 'em up directly here, and then describe your dilemma

oops, sorry yes I've read the rules though I haven't posted on here for a while, link removed

thanks for the info, just searched ebay for washing machine valve and these look bang on the money

Can anyone help me with some maths? the valve I have in mind is rated at 12v 2w. My power supply is good for 12v, 1200mA (max) soooo.....

P = IV => I = P/V
I = 2 / 12 = 0.1666A = 1666mA

too much for my power supply right?

TIA

I`ve used washing machine solenoids, the only thing to remember is they run on 240 mains so be careful around water. You can buy 24v ac irrigation valves for about £21 but also you`ll need a 24v ac transformer. If you know what your doing with mains voltage it`ll be cheaper to recycle.
Most w/machine solenoids will accept a standard hozelock screw-on tap connector (female thread with male hose connector) on the threaded end (3/4" bsp) and a 12mm bore garden hose on the barbed outlet.
A jubilee clamp is useful if you run it at any sort of pressure ..no problem if its for a gravity fed irrigation setup.

patchy at best when it comes to electricals, so mains voltage is a no no. I might be able to rig it up but wouldn't have the confidence to leave it running on its own. Fortunately solenoid valves are used in car fueling systems so there are a few 12v DC valves knocking about. A few lengths of heat shrink tubing will make converting the differing pipe guages relatively simple.

gotta love ebay!

ello again

my solenoid valve is winging its way over from china as we speak

I've put together everything else in my rig and just thought I'd add a couple of notes that may come in handy for anyone building a similar system.

Heat shrink tubing has proven just the job, making tricky joins a doddle and completely water tight. It comes in several guises, offering shrink ratios from 2:1 through to 4:1, heavy duty, light duty, adhesive lined and non adhesive lined varieties. If you're joining piping of differing guages as I am from my reservoir to my piping and my solenoid inlet/outlet to my piping just make sure that both guages fall within the range of the tubing i.e. are smaller than the non-shrunk diameter but larger than the shrunk diameter of the tubing. The adhesive lined stuff obv. offers a more durable join and completely water tight, I cannot comment as to if the same is true of the non stick stuff. The heavier duty tubing requires higher temps to shrink so this should be taken into consideration as there is the possibility of melting whatever you're shrinking it on to. I found the light duty stuff to be more than adiquate, I shrunk it in place using a turbo flame lighter and it took seconds, but a hair dryer should do for the light duty stuff. Oh and it is not flexible once shrunk. It seems to be a bit of a specialist/niche product as none of the DIY stores I tried stocked it, ebay on the other hand had plenty of varieties to choose from. This stuff is so good in fact that I'm looking for other excuses to use it!

now a quick q... I noticed on my last grow if I left water in a bottle with neuts it'd go cloudy pretty quickly. I doubt this'd ever harm my plants but was just wondering if there is anything I could add to my reservoir to stop this happening and not effect my grow?

TIA