[Klean07]

I've got two 1,000 litre tanks one off each gutter that I use to collect rain water ( we've had plenty just lately too)
The last few years I've just let them freeze up but this year I would like to protect them from the frost. Any ideas?

[PoleKing]

Cover them in celotex or polystyrene bud.
The latter being cheaper, the former being stronger and looking better.
I still think they'll freeze unless they're heated though.
Which would probably be more expensive than purifying tap water...
Assume moving them into a garage or she'd isn't an option?

[Klean07]

Maybe I could put a immersion type heater in there to stop it freezing.

[PoleKing]

You could.
But why are you using rainwater?
Is it to save money?
If so, would you not be better just producing 'on demand' in what (I assume) is your already heated van?

[bobplum]

build a box out f fence panels and stuff it with loft insulation and put a top on it

[Klean07]

You could.
But why are you using rainwater?
Is it to save money?
If so, would you not be better just producing 'on demand' in what (I assume) is your already heated van?

I'm on a meter though I use a Merlin when theres a drought 

[PoleKing]

You could.
But why are you using rainwater?
Is it to save money?
If so, would you not be better just producing 'on demand' in what (I assume) is your already heated van?

I'm on a meter though I use a Merlin when theres a drought 

Me too.
But you have to balance out the cost to heat vs the cost to buy tap water, don't you?

[TomCrowther]

I made a v large box type affair in April this year. Just insulated it this week with four inch polystyrene. No plans to heat it though.
I dug down into the ground about a foot, so the base of the tank is below ground level and it's a bit warmer there. Covered it in felt and have a tarp over it as well. Should be good for minus eight or so I reckon.

[Klean07]

Oh right. No chance of me digging into the ground as my two are on tarmac!

[robert mitchell]

Insulate underneath as well and you will be fine .

[H20cleaning]

Buy a koi carp pond heater just leave it on low to keep water above 0