hi guys , i need help ,i have MT 3.20 ,and i have a problem that internet goes slow ,if someone begin to download

i have 30 users , i can know the user who is downloading make the internet slow ,so i use simple queue to slow his download
and fast it for others.

i heard that i can use mangle to do QOS but i read it and i don't understand it well

i only need really help from u guys ,how to make the internet fast and make the user who is trying to download something to have less speed

i have leased line 1 MB upload and 1 MB download

wiki.mikrotik.com

ok
but tell me which topic exactly to read about?