For how long can rainwater be stored?

[Nikki]

I've read so much my head is aching. But I can't find the answer to this. I know that grey water can't be stored for long, and I'm pretty sure that rainwater in a proper storage tank lasts a while, But what about rain water in a plastic butt, how long does it last?

We have a 32,000l tank that collects spring water. But it rains so much during the winter and almost nothing in the summer, and we already have a couple of plastic butts on the land, that we thought of collecting rainwater as well. But I was wondering if it would last months later, into the summer.

[Rod in Japan]

When you say "lasts", do you mean in a drinkable state, or just for watering?

I have a 1,000 litre rain tank connected to my roof, and I wouldn't dream of drinking from it. If it's full and then doesn't rain for a while, it lasts me about 3 weeks of watering. But then I have a fair amount of land, and some new trees that require heavy watering. With a good fall of rain, the tank can fill up in just a few hours.

In the summer, the outside of the (plastic) tank gets too hot to touch, and the last bit of water can be a bit smelly, but not horribly so.

I want to get another similar size butt to see me over the summer months.

[Millymollymandy]

My cat and ducks drink from the water butts (out of a watering can!) and they are still alive and healthy although of course we wouldn't drink it ourselves!

I think it lasts indefinately for watering plants. Ours get filled up in the autumn and the water then isn't needed until we start planting/sowing seeds in the spring.

[Nikki]

Hi guys,

I realised 'lasts' wasn't specific enough. What I mean is that stagnant water goes 'off'. So I was wondering if rain water that I collected in a plastic butt during the winter, would still be okay for watering plants months later in our dry summer.

[Rod in Japan]

I don't think the plants really care. You can keep the water from getting really scuzzy by putting a lid on it, thereby keeping out beetles and lizards which contribute to making it go bad.

[Thomzo]

Hi
I'm pretty sure that there is water in my water butts that's over a year old as I've hardly used them this year. It really does depend on how much debris you can stop from getting in. The ones that fill off my house roof stay pretty clean most of the time. The ones on the shed, which is surrounded by trees, get pretty dank quite quickly. I would say, however, that water full of decaying leaves and rotting insects, is pretty good for your plants, full of nutrients.

Zoe

[Nikki]

Excellent! Thanks guys, I've never collected rainwater before, so it's all new to me.