So the water storage is in, granted it looks a bit rough. I could do with a few 100 litres more to really have enough water and build some thermal mass. However, when life gives you lemons find a way to water them ha... (I'm sure that's how it goes). Anyway, I've moved forward with the DIY greenhouse Watering system and its on task to be finished by the end of the month.
If you missed the post on moving the water butts and connecting them up, it can be found here - Water storage blog part 1
What I got completed
irst bits made was a means to hold the pipes in places. The involved cutting down some scrap wood on the chop saw.
Once all of the wood was cut down it needed screwing together.
I'm pretty pleased with how the pipe holders for the greenhouse watering came out. Granted it may not be the most effective use of material, However, it was scrap and made it simple to do.
2 screws, one from either side to secure it in place.
Below shows an image of the pipework complete for the greenhouse watering of the small herb bed, and rear raised bed. 
One tool that is a great help for this is the pipe shears you can see below. Every cut is square, clean and only took a few seconds. If you do any of this or plan any plumbing I highly recommend these.
Connecting the 21.5mm waste pipe to a standard garden hose or even 15mm pipework seemed to be a challenge. Using a hozelock tap connector proved to be a simple and cheap way to do this and should hold up to the low head pressure of the 12v water pump to be installed.
It seems like I'm starting to get a grip on the situation in the greenhouse/garden and should be back on track within a couple of weeks. At least that is the plan and I'm really looking forward to seeing what this blog can grow into. Any suggestions leave a comment
All the best
Dan