1:5 parts water - eh? what?

[Welly]

At the weekend my Mother was showing me some patio treatment (anti fungus) that had to be mixed at 1:5 with water.

She was adamant this meant 1 litre of 'fluid' with 4 litres of water to make "5".

I think it means 1 litre fluid with 5 litres water; a total of 6 litres of mixture.

I've got a two-stoke mixing bottle at home but it's marked out for you already so never really gave this much thought.

Which is the correct method?

[steve_earwig]

I'm pretty sure that means 5 litres of water plus one litre of jollop but you're right, it is confusing. Goran sold me some screenwash concentrate a few years back, the mix was 10:1 so he said it makes 10 litres, I said it should make 11 but he was adamant it was 10. I'm not sure if the manufacturers know that this is people's usual interpretation and don't bother to clarify or they're actually expecting people to have 6 or 11 litre containers.

When I mix 2 stroke, I put the oil in the bottom and fill the rest up with petrol but this is probably wrong, however none of my 2-stroke bottles has any graduations so it's near the top somewhere and the difference is so little it's not worth thinking about.

[Welly]

To make this clearer* I've just asked the internetz and wikipedia said:

If orange juice concentrate is to be diluted with water in the ratio 1:4, then one part of concentrate is mixed with four parts of water, giving five parts total; the amount of orange juice concentrate is 1/4 the amount of water, while the amount of orange juice concentrate is 1/5 of the total liquid. In both ratios and fractions, it is important to be clear what is being compared to what, and beginners often make mistakes for this reason

Oh f*ck now I have a headache.....

[fattail95]

At the weekend my Mother was showing me some patio treatment (anti fungus) that had to be mixed at 1:5 with water.

She was adamant this meant 1 litre of 'fluid' with 4 litres of water to make "5".

I think it means 1 litre fluid with 5 litres water; a total of 6 litres of mixture.

I've got a two-stoke mixing bottle at home but it's marked out for you already so never really gave this much thought.

Which is the correct method?

The correct way to do it is to find the sum total from both sides of the colon, and that will give you the total volume required in arbitrary units. For a 1:5 dilution ratio, you will have 6 total "units" of volume (litres in this case), meaning 1 litre of fluid to 5 litres of water. This is the only way to do it, anyone that says otherwise doesn't know better

[Welly]

Yes, that's how I saw it i.e. 1:5 mixture would give 6 ltrs of the stuff.

You're welcome to explain that to my Mother though, and best of luck