[BADBACK]

have just put a water but in my
pollytunnel the idea being
when i water toms etc
the water is the same temp
as the plants
and not cold so will not shock
the roots but the question is will
the water go sour or stale
any help please
thanks v much

[Jay The Digger]

No more than outside.  It is a good plan though especially for cucumbers as they don;t like the shock of cold water.

[Carrotcake]

The heating up of the water through the day also makes a bit of a diffeence to the night-time temperature. Great at this time of year 

[compostqueen]

a kind of heat sink effect

It should work well. I used to put a big bucket of water in mine over the winter and come spring clean time I found a bald mouse in it.  Yuk 

[fletch]

come spring clean time I found a bald mouse in it.

Bald? Was it a very old mouse? 

[RichardA]

I have three large waterbutts in my polytunnel. I try to keep water reasonably fresh by using up one barrel completely and only then filing it before using others etc so I dont have several half barrels hanging around -- also mine have good lids. I have not seen any problems. I also have one in my glass greenhouse and several around the garden and all seem to behave the same. So go for it.
R