Micro-irrigation in the greenhouse

This year, as well as the greenhouse, we’ve actually got round to putting in some veg.  Added to the flowers in the borders, when it’s hot, it gives quite a watering load – it was taking an hour a month ago.  That was such a lot of time that I thought it was worth automating some of the watering. So, for a few weeks I’ve been playing.  Some things have worked, some have not worked at all, so I thought I’d jot down some notes to help others who may try the same things.

As well as the hydroponic stuff, we’ve got various things in grow-bags in the greenhouse.  So, I wanted to water these using a micro-irrigation system I bought and had success with in the last house we had in Farnham.  But, it is designed to work from mains water … which we don’t have in the greenhouse.  However, we do have a 12 volt battery powered system  to run a flood and drain hydroponic set-up (see here).  Last year I used the second timer circuit to run a pump to ensure another hydroponic system was topped up once a day.  But, I managed to insert a side-branch, made from micro-irrigation tubing, in the flood and drain pump circuit that puts a dribble into the other hydroponic troughs, and a couple of weeks trials has shown that it keeps them topped up nicely.

So, I now had a spare circuit and pump (a 10 litre/minute caravan water feed pump from ebay) that could do duty to run the micro-irrigation system.  This is now working superbly, though trying it out led to a couple of discoveries.  Firstly, the pressure that this little pump can throw out is impressive – I had assumed that I could manage without the 1 bar pressure regulator (that I planned to use elsewhere), but there were leaks everywhere.  Putting the pressure reducer in sorted that out.  Secondly, I had two branches – one at floor level for grow-bags, and one above the staging, to use for plants in pots.  The pump only needed to run for a minute or two in total, but when it was off, the upper branch drained back down again, and when empty took several minutes to prime (i.e. it didn;t during the time the pump was on.  You can’t get non-return valves for this stuff, but I found that if you put the stiffeners that you use with domestic plastic water pipe down the pipe, then it is possible to get brass compression fittings to be watertight, so I was able to use a standard non-return valve. The feed tank for all this was simply another central heating header tank, which has the benefit of being light-tight, so stopping stuff growing in the tank (the tank at the front is the new one, the rear one is the hydroponic sump :-

Gravity powered micro-irrigation in the veg patch

My next foray was to try and water quite a number of potato and other tubs from the water butts, but using only the pressure from the water butts to do so.  This was as simple as using micro-irrigation tubing connected to a timer that was connected to the water butts.  I found a two-channel water timer in Aldi for only £16 which was a bargin.  Actually connecting that to the water butts was a little more tricky.  I put short lengths of hose with female hoselock connectors on on each butt, which allowed be to gang several butts together using Y connectors, or split the system if I wanted.  These feed a four-way splitter attached to the wall that has the timer on, and also other circuits, such as one to fill a watering can.

I was concerned that the long run (15m) would give an excessive pressure drop, so tried using pressure compensating drippers, but there wasn’t enough pressure to make them drip at all.  So, I reverted to standard adjustable drippers, and adjusted the 9 of them together to balance the system.  It seems to work well, though it takes a fair while to work – we run it for an hour a day.

Soaker hose

The last experiment has been to use soaker hose in a couple of flower beds, and most recently a fair chunk of the veg patch as well.  The first test was for flower beds, with the intent being to run it from a sump pump in another water butt on the other side of the house.  This was, over a couple of hourse of frustrating and very very wet experimentation, a total failure.  The pump, a standard immersion sump pump, simply couldn’t handle any material back pressure down the 1/2 inch hose, and we effectively got no water out.  I was really surprised, given the sheer volume of water that comes out of a short hose from this pump, but I guess it was a good reminder that volume is not pressure.  So, instead we used an old water timer we had on a garden tap that we recently connected up.  This fed one length directly, and via more pipe we laid under the lawn when we put it down. another circuit.

This has worked a treat, though the mains pressure is such that you get tiny sprays coming out of the hose as well as drips. The final experiment (so far) has been to use a chunk of soaker hose directly from the water butts, with no more pressure than gravity gives. I was a little suspicious that this would work well enough (mains only seems to get a bit of water out over time) – but, so far, even with 10 m of soaker connected, it looks good, and it is now on the second veg patch timer channel for a couple of hours a day. You can see the three parallel lengths in the photo below.

And teh joy of this pottering about (and it is just pottering) is that it has taken me less time than the watering would have done – and a lot less water.

There is a new meme that has grown to be almost an epidemic in papers and on-line writing, and it’s starting to really get on my nerves. It is, to be fair, a really useful shortcut to allowing communication brevity, but it is also an appallingly lazy way of avoiding thinking hard enough to make your own judgement, by importing someone elses … and somehow aiming to get credit if it sounds sage or is proven correct, but avoiding anything sticking to you if it isn’t true.  It is of course the ’single quote’.  And, lest you think I exaggerate, 1/4 of all headlines from the BBC news front page tonight succumb :-

Hostages’ bodies ‘found in Yemen’

Tombstoning victim ‘loved life’

‘Flushed puppy’ survives ordeal

IVF couple: Embryo ‘was our baby’

‘Susan Boyle’s fine’ says Morgan

Mexico drug gang ‘boss’ arrested

Israeli PM ‘ruins’ peace chance

Flu risk ’still low’ after death

Herschel telescope ‘opens eyes’

Boyle ‘will sing’ at Glasgow show

Of course it’s not really a curse – but I put it in quotes, so I only meant it if you think it sounds good – if you don’t, then clearly the single quotes meant that I was being ironic.

25 years after the first read, I have just re-read ‘Zen and the art of motorcycle maintenance‘ by Robert Pirsig, and absolutely loved it.  It never was an easy read, cantering as it does through philosophy in a way that does educate you about philosophical positions from a tangent, but only in pursuit of the author’s view on Quality, and how it is the defining force behind, well pretty much everything that has developed.

Whether you agree with the evaluation, the positioning of Quality as a worthy pursuit, and far better than just passively consuming pretty baubles or going through the motions at work is one I hugely support. I know that if I do something I am not proud of, and think is high quality, it hurts me.  That goes for work people do for me as well – if people don’t really care about doing the best they can, I find it much harder to take them seriously.  And, to be clear, doing the best you can do is not about some logical ‘adding the most shareholder value’ pursuit, even though that is a very sensible goal.  It’s about doing it for yourself, and your own sense of pride and self-worth.

One other thing I found interesting in re-reading was the different perception I had.  The first time, I was lapping it up, and then got turned off a bit by the story thread that dealt with madness.  I identified with the narrator, but resented the implication that the point of view could drive you mad.  So, my memory was enjoying the first half and disliking the second half.  This time I was expecting that thread of the story, and actually enjoyed the second half just as much as the first – it wasn’t at all what I had remembered, not so much in content terms but emotional reaction.  Just shows that the frame of mind within which you read something is pretty much as important as the content itself.

This  remains one of those books that everyone should read – I am passing it Alan’s way as soon as his GCSE’s are done.  BTW, you don’t have to buy it to read it, the full text is available on-line – e.g. here, or here.

Recently Sa was given an hours flotation as a present.  It was billed as being as restful as four hours normal sleep (see here - bottom of the page).  That sort of statement gets my antenna up, since it is so obviously a bogus statistic – e.g. could two hours of flotation substitute for a whole nights sleep?  If so then the value of the extra time would pay for the cost of a flotation tank in short order.  But, before being cynical about what is certainly a high bogosity index statement, I realised that I really didn’t know much about sleep at all, which is a real oversight since I spend about a quarter of my life asleep.  So, I thought it was time for some education.  N.B. this post is as much a reminder for me on sources as something aimed to be read by others, so some degree of caveat lector (not misleading, just not intended to be self-standing without following the links).

Wikipedia, as ever, gives a good position on what drives sleep, though it’s a little hard to turn it into useful guidelines for how one should optimise sleep.

There is an annoyingly written piece here.  Lots of exclamation marks which is always a worry in an education piece.  And, statistics thrown about with abandon, and usually without sources.  But, improves a lot as it goes on – worth a read.  Lots of broken links though.  New stuff I learnt was that the owl vs. lark model (aka being a late night person vs. an early morning person) is not really driven by the time of day – instead for owls it’s by a longer circadian rhythm or poor entrainment (the ability to reset the circadian rhythm to 24 hours each day); for larks a shorter circadian rhythm … and that most people really aren’t either.  For myself, I find it pretty easy to reset body clock when travelling, and am definitely an owl, so I guess my circadian rhythm must be at the longer end.

Also, that Caffeine is good for overcoming homeostatic sleepiness (what you get by thinking hard for a long time), but not circadian sleepiness … and that drinking it first thing in the morning may well be a good thing (OK, Sa, I just might have have been nagging you wrongly for 20 years!).

Another source (here) on what is called sleep hygene.  Lists some top tips, some of which counter what is in the previous source.  As a simple example, this one suggests drinking nothing at all in the 6 hours before going to bed … the one before says a small drink is fine and might help.  It also makes some fatuous references to how long bats sleep and that they live in a cave, so dark is good!

Interesting notes on the body clock here.  Notes that lots of light first thing in the morning is good – I’d love to use a light alarm that used lots of light to wake me up in the morning … but not sure that Sa would appreciate it at 5:30!

As ever (though rather indirectly), Wikipedia helps on when light is most useful via an article on ‘phase delay’ – see here.  Basically, within two hours of when you first wake up – though not if you need to wake up to do it!

There is also a truly mind-bending amount of total nonsense described – e.g. anyone fancy turning off all the circuit breakers before bed to prevent EMF upsetting your Pineal gland? (see here – top hint was the ‘33 ways to X’ which is always a hint that it’s got lots of nonsense)

Of course, if you can’t get sleep, then simply reading the links above should help – they are long and repeticious enough!

The UK press is currently spending day after day going through the ‘MP expenses scandal’.  For anyone living in a cave, the UK parliment has basically had a very generous expenses system that has allowed over £20k/year in ‘living in London’ expenses. Over the last few days we have had more and more revelations, and more and more MPs offering to give some components of the money back (maintaining your moat really does sound like stretching credulity).

There have been lots of discussion about lack of morals involved, but what I find more disturbing is the lack of imagination that allowed such a system to be created.  Though I can’t find a reference, as far as I understand it was created in part to increase the rate of pay to MPs without drawing attention to it – presumable through concerns about adverse press.  And, rather than create it as a flat-rate allowance which would look a bit too much like a piece of basic pay, it was structured as a submitted expenses model, with a cap.  Why the concern about lack of imagination?

Well, it was bound to get attention at some point, and when it finally did the fallout was bound to be far far worse than the benefit from avoiding a tough conversation earlier.  The reputation of parliament is being trashed, and that of almost all MPs along with it.  Some appear to be frankly pushing the envelope of ethics to a surprising extent, but that was the system that existed, with an expectation that it got used … so for many MPs they are being forced into defending what was an expectation.

Lets be clear, the crocodile tears of MPs as they try to defend their probity, and talk about their ‘values’ is all a little unconvincing.  Your values are what counts when people can’t see what you are doing, not when you are in a spotlight.  And, some of the statements made leave a really bad taste in the mouth.  The last years worth of trying to hold back the tide on publishing is pretty much as bad – where was the effective internal review in that time?  Gordon Brown and David Cameron could have been reacting then.  The Telegraph can clearly manage it in a few days or weeks.  But, at least as worrying for me is that the group charged with running the country have so little imagination, or so much short-termism, that they allowed such an obviously poor expenses system to be created.  Did they never ask how it would end?

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BTW, this post is written about parliament, but I’ve seen similar choices made in businesses over the years … and it’s no more impressive whatever the circumstance.