Ok, this is how much of a loser I am.... i've just asked on the live chat on the aptamil website!! It seems they're not sure either and I still don't have the answer:
Chloe:
It says on the side of the Aptamil tubs to use 5ozs or 150ml of water... but which is it? 150mls is more than 5oz.
Sue - Baby Care Advisor is dealing your query and will reply as soon as possible.
Sue - Baby Care Advisor:
Hi Chloe
Sue - Baby Care Advisor:
The ratio of powder is 1 scoop of powder to 1oz, or 30mls of water
Chloe:
but 30mls of water is more than 1oz of water which is why i'm asking?
Sue - Baby Care Advisor:
It is 28mls, but it is rounded up on our packets to make is easier for you to make up
Chloe:
so for the purposes of measuring out the formula, we should be using ozs rather than mls, is that right?
Sue - Baby Care Advisor:
It doesn't matter which you use as long as you use the ratio 1 scoop of powder to 1oz, or 30mls of water.
Sue - Baby Care Advisor:
All bottles are different - some only have oz on them, some have mls
Chloe:
140mls is 5oz though, so why wouldn't you put on the side of the tub 5 scoops for 140mls?
Sue - Baby Care Advisor:
What measurements do you have on your bottles?
Chloe:
I have both, which is what's made me wonder where to fill the water to. If I choose to use 150mls for 5 scoops which is what it says on the side of the box, I would be using more water than if I were to choose to use 5oz of water. So i'm wondering - do I use 5ozs of water or 150mls of water because they're both different amounts?
Sue - Baby Care Advisor:
It doesn't matter - there is only 2mls different - parents would find it difficult to measure out 3oz, or 84mls of water
Chloe:
it is only 2mls difference for 1 oz... but when you're talking 5 ozs it's 10mls difference
Sue - Baby Care Advisor:
the ratio of powder to water difference is mimimal - It doesn't matter which one you use