While I am not familiar with the specific brands that you refer to, I believe that it is important to do both. We have a full house filter - filtering out the large particulates/silt helps all the big items that use water - our washing machine, our dishwasher, the toilets, the sinks. Since installing ours, there is much less mineral build up (we don't have to scrub mineral deposits from the bottom of the toilets nearly as often - usually only when we forget to change the big water filter when we should). From the reading my dh has done, it extends the life of things such as our clothes washer. We figure that the whole house filter is very much worth it right there.

The tap at the sink is very helpful as well. Our water is MUCH better tasting, and you can tailer those filters to your needs. Different ones have different abilities. (Getting rid of cysts, lead, etc.) Regarding having a water filter in the kitchen, even if you like to drink filtered water out of the fridge (like my dh) I like to rinse my fruits/veggies with filtered water before giving them to my kids. I also use it in the pots when I boil pasta. Our water is treated, however it is initially from town wells, and I don't really trust some of the things our local water company has done. I don't want to think about it when I have a glass of water or brew a pot of coffee. What will you be doing at the bar sink? Any prep? Grabbing a glass of water? You may want a filter there. Where will you be filling pots for pasta? Filling a large pitcher? Filling the coffee pot? Or making Tea? While the initial cost may seem prohibitive, it should actually be a small amount compared to all of the other items that you are upgrading. And water is much more a "part of you" - If it was me, I would put a whole house filter in, a filter tied directly into the faucet where I was doing the most "prep" of veggies/fruits (that sink's main faucet - not a separate drinking faucet there - it is a bit of a pain not having a prep sink and only using filtered water out of our small drinking faucet) and a filter under the other faucet where the washing up was being done, but with a separate drinking faucet. That way you won't be filtering water that you are using for washing (which reduces the life of the filter). Or, you could always install one for now in the prep/bar faucet, and add one later to the other sink if you find you need it. Of course if you have granite, that may require another hole. So maybe you want to add one to the main faucet, and can always add another one to the main bar faucet (using a different valve under the sink) at the bar faucet. If, however, you think that the bar faucet will be your main drinking faucet, I would add a filter to both now. Sorry. You asked about two and I am recommending three.

BTW, my dh, who is not all that handy, installed a water filter under the kitchen sink. He had some advice from a plumber friend. It didn't take...

Sorry, no answers - I guess I have the same questions (b and c from jjmckillop's blog). We are doing a small remodel and were thinking of doing away with the separate drinking faucet that we currently have, and just adding a good under sink filter attached to the main sink faucet. Is that possible/o.k.? We like to have filtered water for drinking, washing veggies, coffee, etc. and will not have a water filtering system with our fridge.

Any recommendations for an under sink filtering system?

Peacamp, I would still install the whole house filter - because of the large particulates, you will be filling (with those particulates) your sink filter a lot more often (and having to purchase and change it). My dh usually purchases the filters, but if I recall correctly, the whole house filters are not that expensive, as they only remove the particulates and the chlorine taste (though I am sure that those filters can vary in what they are designed to do.)

It is fine to install the under sink filter with the main faucet and do away with the small drinking faucet. You will, however, be filtering washing up water as well, if you use that sink for washing up. That will reduce the lifespan of the filter for drinking water. If you don't mind that, it would certainly be easier for the tasks where you require a large amount of filtered water. I wish that I had separate prep/bar sink - I would just install a filter to the main faucet at the prep sink (along with the full house filter in the basement) with the caveat that we all do what is easiest when in a rush, so design accordingly. Have the coffee area near the bar sink, glasses near the bar sink, and use it for prepping.

Hmm, have I been misunderstanding all this time? I thought the main reason for having a separate filtered faucet rather than just using the main faucet was the way the filter restricts the flow rate, which is why those faucets are always so small. Am I wrong about that?

Just to clarify: I know the whole house one doesn't make much difference that way. I meant the under sink filtration systems.

You are correct writersblock - sorry, I wasn't thinking about that. My dh just said that you are correct, that the filter does restrict the flow. Wherever you put the under sink filter, water coming out will be slower. Not because of the faucet size, but because of the filter restricting the flow. It will take as long to fill up a coffee pot from a filtered beverage faucet as it will a filtered main bar faucet, and he does not at all recommend using that faucet for washing up because of the reduced flow. However, if you are only going to use the bar faucet to drink out of, fill the coffee pot and wash your produce, maybe fill the pasta pot with water, then I think it will be easier to just install the filter to that faucet. We had our under faucet filter attached to our main faucet for two years, and it was slow, but fine. We went with a small beverage faucet with our new sink install for a number of reasons, the primary one being that we only have one kitchen sink, and it did take a long time to do tasks such as washing up. I do wish, however, that the faucet was easier to use for tasks such as washing berries and filling our coffee pot. I would still opt for a slower bar faucet that had filtered water (unless I could find a beverage faucet with a higher arc.) They should make a beverage faucet with a pull out. Wouldn't that be something!

We're fortunate to live in a county with great water (one of the best in the US, or so they claim) so we have just an underwater filtration. We use the GE SmartWater filter system, although we didn't have room for the double filter model which is rated excellent. Filter cost is relatively low which is really important in the long run.

We use the single filter model and are very pleased with it. It has a pretty powerful stream and is on the sink. If I had room for a bar sink I'd put it on that instead; I prefer to keep people out of my work triangle.

I basically set up "beverage central" at the bar at the end of the kitchen. It has a four stage water filtration system, water chiller and instahot. FWIW, the bar also has an icemaker, wine captain, bar fridge (for beer, soda and mixers), small base cabinet (for all the gizmos). Liquor is in the upper cabinets. The bar is between the kitchen and the living room. Glassware is in the cabinets opposite the bar.

I've been living with this arrangement for about two years now. It's pretty convenient to have all the stuff you need for beverages in a single location.

Thanks, hestia_flames. Yeah, a pullout would be awesome!

Thanks you guys! Another potential kitchen disaster averted - we didn't think about restriction of the water flow and we definitely wouldn't want that for the main faucet. So we will be doing the small drinking faucet after all. Maybe the whole house filter later, but that's just not in our budget right now.