I poured over this forum for information about RO filters, and I finally bought a Watts Premiere 4 stage RO filter, and a plumber installed it a week ago. The water tastes great, the install was easy, so far so good.

But, a few days after the install, the water in my toilets turned brown with rust for about a day. When I turned on my faucets, every single one poured out brown water for a few seconds. After a while it got clearer, and now it looks OK.

I suspect this is coming from the city water lines. My 70 year old house has a couple of galvanized pipes in one bathroom, but the rest are copper.

Before we got the RO filter, we used Pur pitchers. I noticed there was often a film of rust on the bottom of the blue filter thing that sits in the Pur pitcher (the pre-filtered water). My assumption is that the rust is coming from Baltimore's ancient water system.

We just had the hot water heater replaced, so the most recent rusty water (it only lasted a single day) must have come from the city, not from our house.

Would it make sense to put in a rust/sediment whole house filter? I fear the RO membrane will be kaput soon if there's dissolved iron in my water.

I looked at the city water report, but it doesn't mention hardness or rust, only contaminants, chlorine (4ppm), fluoride (4ppm), etc. I called the city to ask for a water testing lab, and they pointed me to the water quality report. Do I need another water test if I'm on city water?

I reported the rust in my water to the city the last time this happened, but it takes them a few days to get out here, so by the time they do the test, the rust is gone. Also, my plumber told me there's a lot of rust in City water because of the age of the system.

Here are some of the whole house filters I'm considering that filter rust/sediment/contaminants/chlorine:

http://www.amazon.com/Aquasana-Filter-System-EQ-300-gallon/dp/B0002MIJIQ/ref=sr_1_9?ie=UTF8&qid=1306370381&sr=8-9

http://www.waterfilters-camping-water-purifier.com/multi-pure-wholehouse-TO15000.html

These are expensive ones. There are also a lot of rust/sediment filters that only cost about $40 or so. Are these any good?

About 10 years ago, we lived in the country on a well, and we had an in-line rust filter. Our water was so rusty, I had to change the filter once a week, and it slowed down our water pressure a lot if I didn't change it. Will an in-line filter be a problem on city water? We have pretty good pressure here (the plumber tested it when he was here last week, but I can't remember the number, only that he said it was very good.)

Thanks for any advice.

Here is a link that might be useful: Aquasana Whole House Filter