Automatic watering system

I am sure much has been said about this subject - but I have not found answers to some questions.

I thinks its time to have an automatic watering system. I have so many pots that I feel embarrassed to ask others to do my watering when I'm away, although I do have friends who will help. So I would appreciate any comments from people who have experience of automatic watering. My first target area would be inside my garden room, where it is also difficult to get at some of the pots.

I understand the principle - of having an outside main water supply with a programmable time switch which will supply water, for a set interval of time, down a back bone of large bore tubing (13mm). Short lengths of micro bore tubing (4mm) are attached to this, and at the end of which (or in-line) you have a dripper typically rated at 4 litres per hour, which waters your pot.

My questions are :-

1) Is it practical to have this system running for several months rather than just the few days you are away? Hopefully the answer is yes.

2) Hozelock seems to be the most common system, but there are others - any thoughts on which is the best?

3) Do you need a pressure reduction valve just after the timer. It seems that with a lower pressure you could have less leakage and mess (its going to be inside). Is leakage a problem?

4) Hozelock seems to only have one type of dripper - 4 litres per hour. But some of my pots are very big and need a lot of water and some are small. One size can't suit all. I know you can use more than one dripper - but this seems a bit crude and messy. Claber have 0 to 6 and 0 to 10 litre per hour variable drippers. Is that a better option? or would that be impractical to set up for 40 pots.

5) Its difficult to know exactly how much water you should deliver to each pot, but does it really matter? When you water you are not being very exact.

6) Hozelock have ordinary drippers and advanced pressure compensating drippers. What's the difference and does it matter?

7) Can you mix different systems? The micro bore size on some is 4mm but 4.6mm on others.

8) I will be wanting to change pots around at intervals - is that easy?

9) I also have a lot of small pots - seedlings, young plants etc . Currently they are on 10 large grow-bag trays. It seems simplest to have cappiliary matting on the tray and just water the tray. Does anyone do this? and is there a specific device for doing this?

10) Could I run 40 large pots and 10 trays on one system? I would have a seperate system for outside pots.

Any thoughts would be very much welcomed.

 

Yes. Watch out for clogging over prolonged periods (water hardness etc) and freezing in winter, obviously

If you can get a starter kit that gives you a flying start then go with that, other than that I would buy the various bits / qty you need from a specialist irrigation mailorder outfit.

Yes, you definitely need a pressure reducing valve (and a good micron filter) or either 1) the fittings will blow off! or 2) your water pressure is pants!

Dunno, but from what I have read the systems are likely to perform better if you use the same rated dripper throughout. So put 2 drippers on big plants, rather than one double-rate dripper. And if one blocks / fails the other will keep the plant alive.

Quite. Have one dripper into a container of some sort, and check how much water that collects?

Dunno. Marketing and wallet-grabbing?

My preference would be to stick to the same, at least on one "leg" of the circuit.

If you used to have a model railway, and now you have an irrigation system, you will enjoy the tinkering. If you just want to water your pots it will probably annoy you each time you re-jig.

My plant-rearing [i.e. everything in pots on staging] greenhouse has capillary matting. Works fine. But every pot gets a lot of water (rather than a "little"), and not everything likes it. I recommend that you put micropore sheet over the capillary matting, and if the surface you put it on is not water tight in itself then put down a plastic sheet first (water will drip through the gap(s) otherwise, which means that your capillary matting will dry, before it waters the plants)

You'll have to do the calcs for the number of drippers that you can support on a single leg. Beyond that there are crafty multi-port valves that alternate each time the water comes on. So set the timer for 4 x 1 hours sessions, each separated by, say, 10 minutes and the multi-port valve will supply 4 different pipe layouts, in rotation

The only one I know of is made by Gardena, and looking at the current model it looks way more complex, and expensive!, than I remember, but there are probably other similar solutions


http://www.gardena.com/uk/water-management/water-controls/water-distributor-automatic/

 

A bit late now, but if on holiday in Med/hot countries, have a look in local hardware stores, I was fascinated by all the different bits you can get, they have to conserve/use water more efficiently than us.

 

Ive setup something to water the pots at the front of the house - I went for one of these timers which allows you to have two separate outputs with different schedules - seems to work fine - Ive got a couple of these "aquapod" thingies doing the actual watering, they work nicely but I only went that way so I can (hopefully) stack it all up neatly in the garage over winter - one thing worth mentioning is that they have a dual feed pressure reducer in those kits (like this one but allows you to connect two separate runs of microbore pipe on the low pressure side - they dont appear to sell that separately that Ive been able to find.

 

Is that different to just putting a Tee after the pressure reducer? Sorry if I'm being thick!

 

A good point - and I actually do that in a couple of places so why I thought it was interesting I just dont know. Clearly I need more coffee.

Now - if anyone can find a reasonably cheap timer that I can use with a low pressure source (think big bucket of pre-mixed nutes for the toms) do let me know - I can see this one, but Im pretty sure that this is the same mechanism as this one - so should i just get the cheaper one ?

 

I've never found myself in that position

pretty sure that @JWK has the Darlac one on his low pressure system. Lots of timers don't work on low pressure (as I am sure you know from how you phrased the question).

I'm pretty sure that Gardena have ones that do, probably not cheap though. They do have ones that are "Key card programmable" - which can be handy on, say, an allotment because someone can't come along and twiddle with the knobs. Probably not a consideration for what you are doing though.

 

I agree with Kristen's advice but get it set up and run it for several weeks, before you leave it, to build up confidence/ reduce worry. Also as the weather changes then so will a plants demand for water so it could go from enough to too much or too little.

 

Thank you so much for all your comments. They have been very helpful, and with a bit more Googling its starting to become clear.

My thoughts are running like this :-

1) Although some sites suggested that you only need a pressure reducing valve if your water pressure is very high, Kristen is right - its a must, as well as a filter. This is a long term project and I need to get it right from the start.

2) I have 55 large pots and 10 trays of plants, and I intend to move the pots around. This makes it a reasonably complex system, but the layout is becoming clear

3) By analogy with electrical wiring in a house. There needs to be a water ring main that goes all round the site with lots of extra T pieces (ie sockets) whether you need them or not. This will make for flexibility.

4) Secondary pipes will run off the primary circuit to wherever the pots are situated. If the pots are moved these secondary pipes can be moved or removed without effecting the primary circuit. Both primary and secondary pipes will be large bore. The secondary system is like electrical extension leads that plug into the wall sockets.

5) The tertiary pipes will be the small bore ones that actually carry the drippers. They will run off the secondary pipes just as individual electrical items are run off extension leads. Doing it this way means that when you want to change the layout, you don't upset the primary pipes, but just move, alter or replace the secondary pipes and tertiary pipes.

The pressure drop down a pipe is inversely proportional to the fourth power of the radius. This means that the 4mm small bore pressure will drop 111 times as fast as the pressure down the large bore 13mm pipe. (13/4)^4. So the small bore distances need to be as short as possible.

6) I am minded to use the Claber 0 to 6 litres per minute variable rate drippers. I would start by setting them all at 3, the mid way mark. I could then increase the rate for the large pots and reduce it for the small pots. I will put all pots on saucers, and can tell if I am over or under watering by if there is any water left in the saucer at the next watering time. This way I can make small adjustments for each individual pot.

I think you can mix the systems, as they use essentially the same size tubes. The Claber microtube is slightly larger but their drippers will attach to any microtubes between 4 and 6 mm. I don't think there is any merit in having all the drippers the same size, as Hozelock does. Hozelock says you can have a variable number of fixed drippers in line, and I see that as no different from having a fixed number of variable drippers.

7) I did my watering tonight, and noted that I gave my 55 pots 32 litres of water in total. Without a pressure reduction valve the water supply could provide that in 3 minutes at full flow, but would take 12 minutes when restricted by the drippers. So the water supply seems to be adequate.

8) Overall, I am tempted to use a Hozelock system as its freely available, but with Claber drippers. As the weather cools and less water is needed, I will reduce the timer period. And I think that by keeping the primary circuit separate from the secondary circuit, it should be quite easy to make even major changes to the arrangement of the pots.

 

I suspect that if you bend-double the spaghetti tubes they will not flow. Could be a temporary "shut off" mechanism if a dripper has its pot moved and is not needed for a while?

If you will move a significant number of pots outside, during summer, or somesuch perhaps have some valves on the primary / secondary circuits so that you can turn off whole limbs of the distribution lines?

Not come across the Claber drippers before, but I agree looking at their website the variable ones look handy.

I wonder if a dripper puts all the water at one point on the pot's compost's surface? and whether the "sprinkler" type might help spread that around a bit?


The normal punch looks something like this:

but I found it hard work inserting - arthritic hands probably my problem! - so I bought one of these, which is much easier and "supports" the pipe during hole creation, so perhaps less risk of damage / holes not being "square" and perhaps leaking as a result?


No idea what I paid, way-back-then, but it doesn't look to be very cheap now
http://www.cityirrigation.co.uk/cgi...-Tip---For-4mm-barbed-fittings-MIPBW_3MM.html
http://www.access-irrigation.co.uk/shop/nursery/dripper-components/punch-pliers-3mm


I've been happy with the service from both these companies:

http://www.cityirrigation.co.uk/acatalog/Micro-Irrigation-Fittings.html

http://www.access-irrigation.co.uk/shop/nursery/dripper-components
(although not bought drippers from them).

Access mention that some of their drippers "lock" at the end of the watering cycle, this keeps the delivery pipe full so at the start of the next cycle all the drippers start immediately (otherwise, presumably, the first dripper starts immediately whilst the air is being expelled from all the pipe and the furthest dripper starts "later" - I am doubting this will be a problem for you, less so the longer your irrigation period-duration is?)

Those, and this one (which I've seen mention on GC), come up top on Google
http://www.easywatering.co.uk/acatalog/copy_of_Drippers.html

Or you could have these (which connect directly to the Spaghetti pipe )

 

Kristen - thats great - another very helpful post. Many thanks.

I do appreciate the links. I had a quick look - but they deserve a long serious study, so there is plenty more research to be done.

I really like the salamander and frog. Not so much because they are twee, but because they could grip onto the edge of a growbag tray and I haven't seen anything else yet that would do that. But I fear they would deliver too much water - they are not drippers.

Good idea about keeping, but closing off, unused bits. Because this is going to be a long term venture, my thoughts are towards a flexible system with lots of spare points. Though I might be inclined to use plugs for neatness. And the same goes for having a number of valves in the system.

This raises another point of having a drain point for the whole system. If you start unplugging bits inside a conservatory you are going to get a lot of water on the floor as the whole system drains. Better to be able to drain the system first. I have this on the central heating in my house. There is a drain point outside the house, which is extremely useful given the ink (literally - its ferro ferricyanide the same chemical as ink) in the system.

Thanks too for the link to the hole puncher. I was looking for one of those after watching a video on the net of an American giving comments on building his dripper system.

My current priority is for my conservatory, but after that I would like to have another system for the whole (not very big) garden. I envisage a primary pipe that would run the entire length of the garden - perhaps even a rigid pipe buried in the ground, with plenty of T junctions along the way. You could then attach secondary large bore pipes at almost any point along its length, and be able to service pots anywhere in the garden and still be able to move them freely.

 

They reminded me of Manneken Pis !!

Dunno if your garden is long enough to warrant it (is it a long way to "trail" a hose?), but I have buried a 32mm (rather than 25mm) MDPE backbone pipe down the length of the garden, and I have "stand pipes" at intervals (selected to be hidden behind plants, but also no further apart than a single hose will reach all necessary plants)

I tested 1/2" hose, 3/4" hose and a coil of 25mm and 32mm MDPE pipe and measured how long it took to fill a bucket. On the basis of that I would never use 1/2" hose (except perhaps for a <10M length), and the 32mm MDPE was marginally better than 25mm - relevant for the length of my garden perhaps, but a cost saving to be had using 25mm pipe for sure).

Only downside of 3/4" hose is its a lot heavier to lug about, and you have to walk and sort out where it is about to decapitate a plant, because it WILL!, whereas I might have risked it with a lighter 1/2" hose

I now have some roller-guides on spikes that I stick into the ground where I need the hose to go around something, and they work well (cast iron, came from Germany I think, bought off eBay - rather than something plastic that might not stay-put if just pushed into the ground)

 

My garden is not very long, so an ordinary hose is good enough - except for the kinks and the damage that it can do. I had never heard of roller guides on spikes - brilliant.

I would like to bury a permanent water pipe to the end of the garden, but I have reservations about the effect of frost in winter. So I have just laid an ordinary hose on the surface and this can be easily lifted up to drain the water out as winter approaches.

I have ordered my first bit today, a brass 4 way manifold to attach to my outside tap. The local plumbers hadn't heard of such a thing! Ordering the other bits is not that easy. There doesn't seem to be one site that supplies everything. All sites only stock part of the bits necessary, and there are some incompatibilities. I am planning to use the Claber drippers and their pressure reducing valve, which works at 1 bar (ie one atmosphere pressure), but other people's pressure reduction valves work at different pressures. Claber makes a filter but no one seems to sell it, so I will use a Hozelock one. My local Homebase sells some of the Hozelock range but not the filter.

And you have to watch the postage. I have seen some brass 4 way manifolds selling on e-bay for about £15, but with charges of up to £50 for postage.

What I haven't seen yet is a mechanism for adding feed to the water. That would be useful as I will have to feed everything manually even with an automatic system.

 

Kristen - I would like to thank you for your help.

I have just ordered all my parts. It wasn't easy as no company supplies all the bits I wanted. Hozelock is the most comprehensive but they don't do filters or low flow adjustable drippers. And no site supplies all the bits either. Hozelock work on 1.5 bar (atmospheres pressure), but the Claber drippers that I like work on 1.0 bar and would presumably deliver 50% more at 1.5 bar.

I have chosen mostly Hozelock bits from http://www.easywatering.co.uk/ which seems to be generally the cheapest. But I had to buy a filter and the hole punch from http://www.cityirrigation.co.uk/ I then noticed that they did packs of 25 T pieces and stoppers for a similar price to the 10 packs from Easywatering - so I bought some of the bits from there.

I have reluctantly decided to mostly use the fixed rate drippers from Hozelock, but I will experiment with some variable rate ones from Claber. When I was watering last night I used a moisture meter on each pot and found that nearly all were very wet, although about three were dry. This makes a nonsense of trying to give them exactly the right amount of water.

Nearly all my pots that will have individual drippers are pretty large - so they might have similar requirements. All my small pots, which obviously need much less water, are on capillary matting on trays and so will receive less. But it will take a bit of experimentation to get it right.

The good news is that even if the system is not totally right, it will do the watering for the times that I am away.