new project "our first greenhouse"

i am just planning and prepping for our new greenhouse which as been kindly left to me and my wife by her uncle, who was a very keen gardener and great bloke god bless him.
the position where im putting the greenhouse in the garden is sloping, so i plan on putting flag stones on edge to provide a level base for the alluminium frame, and then maybe a slatted timber shelf to put pots on(which will be nice and level).
i plan on putting power to the greenhouse as it will be quite easy but i think im going to use the hose pipe for water to start with.
ive cadged some old tube heaters which i can use to stop frost when connected to a thermostat.
im still looking at ways to keep it cool for the one or two hot days that we get, ive seen you can get automatic window and vent openers for about £20 each on ebay.
i still have to take down the greenhouse and fetch it home, but in the mean time a few of the things that i need to consider are,

i have two young children so breaking glass could be a problem as i dont think it will be toughened, my little girl was 3 last week and is clumsier than me.

the greenhouse is in my garden and i dont want it to be an eyesore, which they sometimes are, but i suppose it depends whats in them as they are made of glass.

ive been reading about hydroponics and autopot systems and really like the idea of it, but its really expensive so im thinking of some kind of diy system as cash is an issue.

theres also some bits and bobs, including an home made propagator, some bubble wrap and some bits that fit in the greenhouse channel, so thats good.

ill post some photos as i go, heres one in its current location(hope i can move it without two many breaks, i noticed a bit of silicone here and there so it wont be easy)


i hope to have it ready for spring, and would like to grow tomatoes, cucumbers, bell peppers, chilli peppers and maybe a couple of grape vines
if anyone as any ideas or suggestions on things i should consider before i get started please let me know,i wont be starting for a week or two.
im especially interested in the hydroponics side of things, but i can sort that out later.
thanks
joe

 

Are we talking mains power? If so you really ought to have an electrician do it. If you do it yourself, you really ought to be sure to include an RCD (Residual Current Detector) as it is outdoors - basically these detect if current is leaking from live or neutral to earth, which would happen if someone was in the process of being electrocuted. Its not the same as a normal circuit breaker, which is designed to trip if there is too much current, but it only takes a few milliamps to electrocute a person, nowhere near enough to trip a normal circuit breaker.

Keep the glass clean. There's nothing more unsightly than a dirty old greenhouse with glass so matted that you can no longer see through it. If its clean it should be ok.

Here's an idea, which might be a crazy idea, but I'm going to put it out there anyway. Laugh and mock if you wish, but I had actually thought along these lines at one point myself. For hydroponics, as I understand it, you need something that will spray a mist of water and nutrients directly onto the plant's roots (or is that aeroponics? I'm not sure). Looking at the price of equipment, I dismissed that idea as too expensive. I then got to thinking about what it does, and what we need to recreate it. We need a small water pump, a container to store our water/nutrient mix in, and some sort of spray nozzle. Hmmm I thought. Something like the windscreen washer arrangements in a typical car. The scrappy would sell the washer bottle and pump as a single item, and the hoses from it and the spray nozzles would be cheap enough also from the scrappy. Then just a 12v power source, such as a transformer (available from anywhere) or a car battery (again from the scrappy).

I have no idea if that would work, but it was just an idea. It also doesn't cover how we would arrange the plants so that their roots are exposed, or how we would catch the excess spray to go back round again, but its just an idea.

Now, permission to laugh and mock me for my daft ideas duly granted

 

thanks for your input clueless1, and thanks for putting my safety first,

all the sockets inside and outside my house are on an rcd through my main fuse box, and ive already got power around my garden by way of armoured cable, so i think allswell there.

as for the hydroponics, sounds great, i love scrapheap challenge, but they've never been asked to grow a tomatoe:lollol:.
maybe what im thinking of is just automatic watering.
the "autopot" feeds the plant from the bottom by use of a kind of tiny ballcock valve, fed from a water butt, where the nutrients and ph and whatever else is needed are measured manually , no need for electricity,(i know i said i was putting in electricity, but that was mainly to stop frost and for the propagator) , it all works very similarly to a toilet cistern except that it fills the trays upto about 25mm (1") deep, and then doesnt refill untill it is empty.
you can buy the "auto valve" for about £10 which is quite reasonable as plumbing bits go, but if you buy the full kits it is extortionate.
so if water finds its own level you should be able to use just one auto valve to feed a full greenhouse.
thanks for all input to this thread
joe

 

i have to ask,
tomatoes send out roots for water, does it matter if they are always wet?

 

Hi Joe
If they are in saturated soil they will probably suffocate and/or get root rot. With hydroponics (flood/drain, dwc, nft or something similar) as long as the water is well aerated and not too warm they won`t mind being wet.

 

thanks hex,
ive been looking at the autopot systems, but there quite expensive so i was wondering if i could design something with a tank and ballcock, but the water would always be there, at what ever level i set it at, where as the autopot smart valve fills the system with an inch of water, then when the plants have used all the water it fills the system again, and so on.
ive since seen that you can buy the smart valve on its own for about a tenner, so i suppose that would be an option.
i imagine that if my set up is nice and level, one of these could manage the whole greenhouse.


im still reading up on the subject and may go for the flood and drain system.
a couple of quick questions
1. all of the mediums that are used in hydroponics are expensive, is there a cheap option, can i just use compost?
2.if i do use one of the proper mediums, what size pot would i need for tomatoes.

i also came across these trays while trawling the web, there a metre long, not sure what size pot you put in them, but they only cost £4 each. i think they are too small for toms but they might be ok for chilli's or something else which is small.(any suggestions)


it says to use 1m grodan slabs

they are also £4 each and measure 100cm long x 15cm wide x 7cm so i suppose the plastic tray would fit 150x150 plant pots
this is how they are meant to be used.

i still havent decided on the position of the greenhouse. no rush tho.

 

just to let you know, ive scrounged an old pond pump and 2 water storage tanks with ball cocks, from an old central heating system.(every body goes for combi boilers nowadays, and that makes the water storage tank redundant, so not too hard to drop on)

 

Hi Joe
If you can handle the extra weight, well washed gravel is just as good as hydroton and a lot cheaper. If you want it to look nice you can use a few inches of hydroton on top of the gravel.
The best container would be quite deep (12"), a plasterers bath (4ft x 2ft x 1ft deep) are a good size and very sturdy.
For flood and drain, fit a standpipe into the floor of plasterers bath using a tank connector and drill a small hole or two in the side of the pipe near the bottom. Place a larger diameter pipe with lots of small holes over the standpipe to stop the gravel blocking the small holes.
Run the pond pump on a basic timer 15min on/45min off. The pump needs to outrun the flow from the hole(s) in the side of standpipe so the plasterbath fills with water.
When the timer switches off the pump the water drains slowly from the bath back to the tank via the small holes. Set the height of the standpipe to act as an overflow to prevent the pump overfilling the bath. A plasterers bath holds about 160L of gravel so you`ll need 65L-80L of water to flood it.

 

thanks again hex,
i dont think i've got a good grasp on the hydro idea, after reading your reply with the 15/45 minute watering ratio, compost obviously wouldn't drain that quick.
just to be clear, if i used the plasterers trough like you suggest, would there be any pots inside it?

ive had a couple of hours today trying to workout where the green house is going, i'd read that it should be positioned with the ridge facing north to south, but im going to have to plant it east to west, to suit the layout of my garden, i think it will all look ok when its done tho.
just need to put some kind of boundary around it for the safety of the kids, and my drunken freinds when i have a fire. "i love a good fire" right time of year tho,
good old guy fawkes.

 

ive just been reading up on the pump that my dad gave me, its a serious piece of kit. hozelock 1552, it'll pump 4500 lph, thats a 20 litre bucket in 16 secs.
it also has a uv lamp built in to kill algie, im not sure if thats a good thing or not, will it also kill the nutrients?
if so, i think i can remove the bulb.

 

Hi Joe,
You wouldn`t need pots and it allows plenty of room for tomato roots to spread out. The freeflow (zero head) output of your pump could,in theory, run upto 14 plasterers baths. You can always tee the output and use the excess flow to aerate the nutrient reservoir. UV will oxidise trace elements in the water column so not very useful

 

thanks for all the input hex, you certainly know your onions, .
i found a method on the net today called "wilma", it looks quite simple and i think it'll suit my set up perfectly.have a look at this sketch i did earlier,

the greenhouse is going to be on a bit of a slope, so i would be able to put the water storage tank underneath the raised level floor at one end. i also thought that if the pump is left on for a few minutes causing the highest bucket to overflow it will put air into the water.
what do you think.

 

It`ll work but the lifting the water seems like an extra step you don`t really need, i`ve modded your graphic with tee after the pump and added a tap to direct the excess flow back into the greenhouse reservoir tank which will aerate it when the pump is on. Everything else can be as is although i`m not sure where the pipe from the righthand side of the return gutter goes. I see the lefthand side returns to the greenhouse reservoir and a tank outside the greenhouse supplies the greenhouse res via the float valve.
I`m not sure if you plan to use a soil based system and plain water to irrigate or a hydroponic system with an inert media (hydroton,gravel etc) along with a nutrient solution

 

thanks hex, i like the way we're going here, i still don't know whether i'll be using soil and water, or hydroponics, or can i do a bit of both? i think id like that.
as for the alteration you made to the set up, I'm glad you did away with the bucket at the top as i had'nt worked out how to suspend it,(might have looked a bit untidy from the outside aswell) id already knocked up a couple of bits of pipe to see if the pressure from 2metres would have been enough to make drip feeders work (they did).
just so im clear, on the new layout, the tap could be adjusted to create the right pressure for all the drip feeders?.
another quick question, can spray heads be used in the same line as drip heads?
by the way i've got some more bits to work with,
25x 15 litre pots

a cheap irrigation kit

and some good quality irrigation fittings (gardena and hozelock) that work with the cheap kit

heres where the greenhouse is going.

from the highest point to the lowest point its 500mm out of level in the length of the greenhouse

you can just see the string that marks it out

and down at the bottom is my steptoes yard.:thmb:

 

Hi Joe
If the sprayheads use the same pressure as the drippers then no problem, if they need a lot more they`ll need a seperate line from the pump and a tap to control the flow. Its probably worth fitting a manifold to the pump so you have upto 4 adjustable outlets with hozelock connectors for plug and play additions. The pump has plenty of ummph.
Thats a fair bit of slope, i thought mine was bad