I store water for when the main supply goes off in the big ( drinking water ) bottles from 7/11. As they are outside, the water has gone green.

According to the internet, for drinking water, add 3 drops 5% bleach per litre.

Anyone have experience with my situation? Is that enough bleach to stop the water going green?

I don't want to use them for drinking water.

I put in a capful per approximately 500 liter in my 1500 l tank (which is on a pressure pump to the house). That is enough to inhibit algae growth for me.

Keeping the bottles out of the sunlight/in the dark will also help, simply because algai needs sunlight to grow. That's why water storage tanks are not transparent.

Keeping the bottles out of the sunlight/in the dark will also help, simply because algai needs sunlight to grow. That's why water storage tanks are not transparent.

Don't have enough space inside to keep them out of the sun. Would some black plastic work?

Thanks for the replies.

Anything that keeps the light out.

How about the green or black netting that you can buy everywhere.

Anything that keeps the light out.

How about the green or black netting that you can buy everywhere.

But that netting only providing shading; it doesn't block all light.

Keeping the bottles out of the sunlight/in the dark will also help, simply because algai needs sunlight to grow. That's why water storage tanks are not transparent.

Don't have enough space inside to keep them out of the sun. Would some black plastic work?

Thanks for the replies.

That should definitely help since it blocks the lights. Also be sure to completely fill-up the bottles to minimize the amount of air in the bottles.

Thanks for the replies.