Hi i am hoping someone can help me work out the ratio of Trigene in litres, ie how much trigene do i add to a litre or 2 of water, i know it says 1:200 on the bottle but i am not sure what this means in Litres. I realise i am a bit thick but i would rather ask than make a mistake, many thanks Freya.

At that ratio you'd add 1 centilitre of Trigene to 2 litres of water.

5 ml per litre (1000 ml) :)