I had one of my customers say the same thing after a new install. I don't know if it came from the glue and cleaner I used to connect the PVC pipe or the system itself. I installed a 10" filter housing with a CBC carbon filter after the system and she now loves her water. Maybe you could get the salesman to install this free of charge.

I don't have a whole house carbon filter but when we did change the carbon water filter on the fridge it tasted a bit plastic-y for a while and soon it went away.

I have a KDF-85 filter in my softner tank and not carbon and never had any taste problem. Cost only $200 installed.
http://www.qualitywatertreatment.com/media_guard_filters.htm

$3000! wow. My system is for a much bigger house than yours and cost much less.

Well, it has a 1 1/4" control valve for 1 1/4" lines and that seemed to add a lot to the price--the ability to handle higher flow rates with a 1 1/4" valve. IIRC, going from a 1" valve system to a 1 1/4" system bumped the price from the $2k range to $3k.

The 14x65" tank itself already is a combo softener and carbon filter. It's already got 18 pounds of carbon in it. I cannot believe that the water tastes this bad now.

BTW, I called the company who installed the original system and who did most of the neighbors' houses when they were built in 2001. That company is Water Techniques (formerly Water by Design) and they quoted me $4,482 for a 1 1/4" system with a slightly smaller tank (12x52). Culligan was $1,137 cheaper and its tank was larger capacity. I don't know how much similar systems cost elsewhere, but they sure are expensive here. Those prices included 7.75% sales tax.

In any event, I am very concerned about the bad taste. Anyone else have any thoughts about it?

Softeners with combination media (resin for softening and carbon for chlorine removal and taste) often do not do what the salesman say. Best to have a softener and a separate backwashing carbon filter if required to treat a specific problem.

I'm wondering if you have sufficient water pressure and SFR (Service Flow Rate) to adequately backwash and regenerate the 14x65 resin tank you have.

Regardless, get Culligan back there to make whatever adjustments or changes are necessary to provide you the water quality you expect and paid for. When Culligan can demonstrate that your water is zero hardness all the way until regeneration and passes your taste test then they're done. Simple as that.

I have really good water pressure here. The pressure coming in on the main is 110 psi (I know because my house is fire sprinklered and there's a gauge on it.). The main goes to a reducer at the front of the garage before it hits the internal plumbing. I forget the exact pressure coming out of the reducer but it was strong. I have 1 1/4" copper mains into and out of the softener/filter.

I have Culligan coming out tomorrow to test it. I invited the salesman over to the house to taste the water, too. They say that they have no idea why it should have an off taste given the carbon filtration. We'll see what they say tomorrow.

Culligan sent out two technicians today (the second guy was experienced in the field, but new to Culligan, so he was on ride-along). They were both friendly.

The main guy tasted the water, noted that it had a taste, and said that that was how soft water tasted. The other guy tasted it and he did not care for the flavor.

On the one hand, they wondered whether the carbon in the tank needed to "settle in". But on the other hand, they said that the softener was removing magnesium/calcium and replacing it with sodium--and that carbon would not change that if this is simply the taste of the soft water.

They asked me to keep the system in place for another week or two to see if the taste goes away. Culligan has a 30 day guarantee, so they will take the system out if it does not resolve. They also said that they would offer to swap the tank with a new one, before yanking it, if I remain dissatisfied.

I still find it hard to believe that soft water is supposed to taste like this. I have to believe that I would have read or heard about it in my research and in my discussions with people who have softeners.

So I guess I am in a holding pattern for the next week or two to see what happens.

The higher the hardness of the water the more sodium (or potassium) ions are exchanged for calciums and magnesium ions.

Discerning pallets can taste the sodium (or potassium) but I've never heard that taste described as plasticy. 15 grains is considerable hardness but I doubt that the sodium (or potassium) is the taste you describe.

Carbon doesn't need to "settle in". It removes chlorine and mitigates taste as soon as the water runs through it.

As I stated, combination media as in resin and carbon rarely perform as the salesman say it will. A separate softener and a separate backwashing carbon filter works better.

Have you asked your neighbors if they are softening their water and how it tastes? If you're on a municipal water system that has that much hardness chances are you won't need to go far in the neighborhood to find neighbors with softeners.

Let Culligan know that you are counting the days till 30 and if they have not resolved the problem have they will remove the system and refund the total amount you have paid.

Then you get to start from square one and find a local water treatment professional who will resolve the harness and taste problem.

sounds like resin is bad, there is bad batches that make it into the market every once in awhile. Bad resin well throw off color, odor or taste. Put the softener in bypass and see if the taste gets better. If it does then you know its the resin.

Little off topic, our softener is only for hot water. For drinking/cooking we use water from separate 7 stage RO system. If you have whole house plumbed for soft water, trace of salt will be in the water. Some articles about this out there.