We want to install a whole-house water filtration system to remove chlorine and other stuff from water. Will this affect water pressure? it seems that any filtration system must put resistance to the water flow, so there must be some negative effect but how big is it? Also, are there any sort of "water pressure amplifiers" that could be installed in the house -- with a filtration system or not -- that would increase pressure? We already have an issue with low pressure in one shower, so we do not want to make the problem even worse. Thanks!