I would probably just do the whole house one, but... what's the price to install the one at the sink? If it's minor, then I'd say do both for your own peace of mind. :)

I've actually been looking into these recently as well. Do you know much about the installation - who does it, what the costs are, etc. I saw a whole house filtration system for $1200 and thought that's not bad, but then wasn't sure what the hidden costs are for installation. Any info you've gathered would be helpful!

I have been told that you buy a two filter system: one for sediment and the other for chlorine, etc. They are installed at the point of entrance where public water comes into the house. In my case, the filters will go under the house but in an accessible area (although I can't imagine what is easily accessible under the house). My partner and plumber will set it up. The filters are around $250-300 (total I believe) and have to be replaced once every 6 mos or so. However, my partner seems to feel that once every nine months is more than adequate. He will buy the filters through a company that does the filtration systems for vineyards, but I don't know the name or location of the company. If you want, I can find out. He's probably dealt with them in the past for our well (on our other house in the country). As if water isn't expensive enough, now we've got to pay for ongoing filtration systems.

Have you had a water test done first to determine what needs to be filtered out of the water? Have you matched the filters to what you need to filter out?

Deke - No I haven't done a water test. This is L.A. city water -- it can't be good and we know it's loaded with chlorine. So my first priority is a filter for the chlorine (carbon), which also filters out a lot of other chemical byproducts. The sediment filter is for sediment -- rust, sediment, earwigs. Lol. (We had to take apart our faucet because an earwig got trapped in there somehow.) It's a fairly standard two-filter system.

Filtering water is a science. There are different types of filters, which is why you first need to know what it is you need to filter out of the water. LA has different sources of water, with some areas having harder water than other areas, so you may also need a water softener. You really need to get your water tested first in order to know what you are dealing with, and proceed from there. Your argument would be much stronger if you can show your partner the facts about your water.

If you are worried about the quality of your tap water, and are getting a whole home water filtration system that consists of 2 filters, you really aren't removing much from the water. To remove industrial waste, toxins, pharmaceuticals and all chemicals, you will need a reverse osmosis system. But, if you want a whole home system, I have seen a system (which I recently purchased even though I have an RO system for my drinking/cooking water) that is under $200, not including the charge for installation from Aquasafe System, which includes the sediment filter, and a carbon filter. And the replacement filters are under $60 to replace.

Here is a link that might be useful: Aquasafe Systems

From my understanding, it's ideal to have a whole house system to remove chlorine and then separate, small RO systems for drinking and cooking.

Hopefully an expert will chime in.