Adding whole home water filter to the main water line line
I would have to question your reasoning for filtering all the water you use in your house. Filtering can get expensive when you start having to replace filter cartridges, especially those rated to take most of the nasty things out of the water. It really is a waste in most cases to be using filtered water to flush toilets, wash cloths, shower and wash dishes. 

It is a lot more cost effective to install a filter at one location, such as at the kitchen sink, where water is filtered to a separate valve for drinking, cooking and to feed the ice maker in the refrigerator. 

If your reasoning is based upon hard water that has a lot of dissolved minerals or iron in it then there may be better choices to use a water softener rather than a filter.