Help with design of garden watering system

[dinga]

G'day

Be easier if I could pay someone around Klaeng to design and install an automatic watering system for our house garden, but haven't found anyone who is remotely interested - hence this pretty clueless bloke is hoping for some help from you guys.

General thinking

* use a stand-alone electric pump, located next to - and drawing from - an above-ground 2,200 litre storage tank (max water level height above pump of 1.5 m)

* controller with timer and switch/valves for 2 sections. Each section needs approx 50 litres per minute for bubblers/sprayers/sprinklers etc

* use plastic LDPE PN4 20mm (Max 2.1 Bar; Min 1.6). A length of approx 35 metres of LDPE pipe for each section.

Appreciate all advice - but especially in relation to:

1. Is the general approach reasonable? Is LDPE OK

2. What type and size of pump?

* been looking Mitsubishi and Hitachi models. Looks like Hitachi may be better as the Mitsu's with the desired discharge capacity have higher On/Off Pressures (2.2: 2.8). Assume this is no go for the LDPE as too high

* Hitachi WM-P200GX2 might be OK - it's a Constant Pressure type, with a maximum stated capacity of 49 litres/min - On/Off 1.6; 2.2 Bar). Is a Constant Pressure pump OK for this application, or should an automatic pump with a pressure tank be used? Is the 49 litres likely to be accurate ie. is there some tolerance of +/-? Will there be any appreciable problem if it delivers 49 litres (or say 48 litres), and I figure system need is 50 litres? Guess may be more a problem if the actual output is gretaer than the 50 litres.....

3. Recommendations of where to buy the pump and sundries (preferably Rayong/Klaeng but Pattaya also OK)

Apols in advance as I'm pretty clueless!

[bankruatsteve]

Watering the garden is for me something to do - so that's one of my jobs. If you need automatic, it sounds like you have it scoped out pretty well. As for pump, I would just go with the basic no brand low power that you can get from the local shop for B1500 or less. We did that for our bamboo farm and it happily pumps from a 1000l tank for less than 3 baht/hour.

[LivinLOS]

If you look in the smallholding gardening section you will see I was posting about water timers..

I just bought 2 and will go get a 3rd next time I am near the hardware shop.. Tho much smarter would be to contact the suppliers in the thread for the dual output ones.. Hell I would really like a 4 output one now I see how useful it is..

I made up a blue pipe branched 'input' with a timer on each output.. These I linked into some hose piped runs to sprinkers and misters.. Running no more than 2 at a time.. But switching in sections to cover multiple zones.. I am sure my house water pump would run more than 2 if it had >1/2 inch pipe running the location where I put the timers. Whole thing has cost me less than 2k and is covering a bunch of lawn, a load of pot plants and the like.. This could scale up super easy and for really cheap, I just wanted to cover an area of garden and plants close to the house.

Adding 2 more timers and some of that bargain basement misting kit would allow me to cover significantly more and all from a single 1/2 pipe by staggering each timer 10 mins. If I had a larger pipe from the pump to that bit of garden I could do more on each branch, I am bandwidth limited if I dont want to start digging up and running fatter pipe.

One unforseen drawback is the missus now wants to go buy loads more plants, now its automated watering she wants to get more of it !!

[IMHO]

What type of spray heads are you actually looking to implement? pop-up lawn heads? misters? drippers? sprinkler heads?

If you want actual sprinklers, no way will 20mm PE pipe suffice for the whole thing. For example, If talking pop-ups, 25mm can tee off to about 3x 20mm pop-ups. 40mm PE can support 2x 25mm feeds to pop-ups etc. Get an irrigation specialist to look at your layout and advise the size pipes you actually need to insure all heads get adequate + balanced pressure & flow.

Also, you absolutely don't need a constant pressure type pump for this usage. You can also forget about bar (other than keeping it within pipe capability) - the spec that matters is flow rate.

Edited March 13, 2015 by IMHO

[kamalabob2]

There must be a motivated Netafim drip irrigation dealer in Klaeng or a Hunter lawn sprinkler dealer in your province. I've seen the RainBird sprinkler importer booth at a previous Architect Expo in Bangkok. I've spoken to both the Hunter sprinkler design representative and at length with Sutouch Yamngam who is the Buriram Province Netafim drip irrigation technical advisor. Mr. Sutouch Yamngam is fluent in English and Thai, but my wife had to translate for me with the Hunter Sprinkler representative. If you do a google search for the brand you may find the distributor in your province who is willing to provide personal customer service and a written price quote. "One unforseen drawback is the missus now wants to go buy loads more plants, now its automated watering she wants to get more of it !! " I understand 100% the situation of LivinLOS!!

You can often see bi-lingual representatives of lawn sprinkler companies or drip irrigation firms at Expos which are held in most provinces of Thailand.

[dinga]

Thanks for the inputs - which I'll take back to the drawing board. Will let you know how this all works out.

BRs