keeping rainwater clean

[solway cropper]

Being an avid home brewer and wine maker I'm used to adding metabisulphate to things to sterilize them, prevent fungal growth, etc. My question is: can I add some metabisulphite to my rainwater butts to stop algae and will it harm the plants....i'm thinking very small amounts. Like most grow-your-owners I'm reluctant to buy anything if I can improvise with what I've got....or is that because I'm a Yorkshireman

[Snadger]

Simpler to put a cover on your water butt? Without sunlight water stays clear!

[rustylady]

Agree with snadger, use a lid. Also, fit a filter to the downpipe that feeds the butt. The foot out of a pair of tights secured round the pipe with an elastic band works wonders.

[solway cropper]

So that's what the lid is for...I thought it was to stop the sparrows falling in and drowning

Trouble is I have two large butts full of green water cos I forgot to replace the lids after doing some reorganizing of things around the garden.

[rustylady]

The green water probably won't do any harm if you use it for general garden watering. Just don't use it on seedlings in the greenhouse

[Dynamo]

The green water probably won't do any harm if you use it for general garden watering. Just don't use it on seedlings in the greenhouse

Also, if you do put the lids back, on the algae will die off and sink to the bottom leaving the water clear again.