Rainwater for the hoofy ones

[SurelyYoureJokingMrFeynman]

Livestock numpty here, especially wrt UK standards. But is stored rainwater considered suitable drinking water for horses here?

I'm wondering whether to do a two-birds-one-stone job and offer my neighbour the run-off from our house roof, possibly going halves on a tank to store it in the field. It would save me the expense of rebuilding a collapsed rainwater drain.

But the water would end up stored for a long time, as I'd want a tank with good capacity (if it overflowed regularly I'd have to rebuild the drain anyway, to avoid damp issues).

Will I look like an idiot if I suggest this to neighbour?

[chocolatecakeystuff]

They can drink rainwater - but personally I wouldn't use it as my main water source for mine... especially if it's been standing a while.

[Plomino]

We have a rainwater collection system that takes everything off our stable roofs and holds it in 3 thousand litre tanks , that are then raised on railway sleepers to sit above our hay soaker , and we use it to soak their hay with , and have done for years with no ill effects . It gets used all winter , then emptied and cleaned out when they're out for the summer . It also gets used for the occasional bath , but their drinking water comes from the mains , which is again recycled the following morning into the hay soaker . Saves us a fortune in water .

[Mirage]

I've never used anything else.We have several tanks in the farmyard which the gutters run into and have always used this for everything.

[SurelyYoureJokingMrFeynman]

Thanks for thoughts.

I've just worked out the average supply would be about 4000 litres a month. Obviously more during long wet spells.

So unless there's some use for at least 4000 l/m, at the wrong end of the field for the stable, I'd need the drain anyway.

(Field currently has three ponies, btw, which I'm told is the comfortable number for it.)