Hello All. we recently moved into a new property and i've been making some changes to the plumbing. the initial problem was that the gravity fed hot water was really really poor. So i fitted a 3 bar Salamander pump CT Force 30 PS on the exit from the hot water cylinder (using one of the Salamander S tank flanges). This works brilliantly and the hot water pressure is now very good all around the house. on the sinks with a separate cold/hot tap I don't have any issues. on the mixer taps (bathroom/kitchen) which have a cold water mains feed everything seems to work very well.. both the hot water and cold water mains are under pressure and the mixer taps work fine. Our two showers that take a cold feed directly from the cold water tank in the loft and this is under very poor pressure, so the hot water pressure is over powering the cold water in the manual shower mixers and the hot water is back filling the cold water supply back to the cold water tank. my initial plan was to take a feed off the cold water mains entering the cold water tank and using that to feed the cold water to the 2 showers as this seems to work well for the bath and kitchen sink. however i read that this is not necessarily a good idea as the cold water pressure can fluctuate and cause simple mixer showers to fluctuate in temp. is it really such a bad idea to use a manual mixer when the pressures might be dissimilar ? would this not just be the same thing as when some herbert turns on the hot/cold taps elsewhere in the house and causes a sudden spike/drop in temp ? if its really that bad what the next step ? would a set of thermostatic mixers deal with the issue ? Cheers in advance for any help.... C.