low shower pressure

[mush]

i have a mixer shower. cold is mains fed. hot is same level,water tank fed. i wish to boost the pressure on both feeds but have been told that i can't use a shower pump connected to mains feed.
is this information correct?
if so,how do i get around this problem?
thank you for your time.

 

[Bahco]

You must have brilliant hot pressure if your cold is off the mains and the shower is working properly.
Your cold should be fed off the tank so that the pressures are balanced.


You can fit a pump if both supplies are fed from the tank