washing powder,which one is best?

[bubbles4]

for years now i,ve used wasing powder tablets but recently have noticed that they are not so good as removing stains as they used to be. read on washerhelp site that big box powders are better for stain removal and for keeping machine clean, so which is the best?

tesco biological

thats what ive bought but how much to use theres no measuring cup and it says 100 grms i am not weghing out washing powder ,dh will think i,ve completely lost the plot!

bold