[Hi Ken,
Funny, isn't it? I think that the problem with blanket statements like we must all use R/O is just another myth that needs a little tweaking. The reason I say that is that everyone's supply water is different. Now I get my water in Grapevine from the same place that Marc gets his from in Fort Worth, but the lines to my house are different from his in Fort Worth, so there might be more iron or even more chlorine or phosphate in mine by the time it gets here. Also, our water supply is taken from several different sources. Most of Trinity Water Authority water is pumped all the way here from the Chambers Resevoir which is about 100 miles from here. It is pumped to several different lakes in the Metroplex. Each of those lakes has unique mineral traces. Now from month to month and year to year, my water quality changes. Having been at this address now for 6 years I have seen my 1 micron sediment filter change colors from brown to green depending on where the water comes from, time of year, and the drought situation. Very wierd I know, and I can't speak for everyone, but that's what happens here at my house.
My other latest problem has been a lot of phosphate and iron in the water supply. They use phosphate to keep the pipes clean or something, and although it tests low, it does and has fueled green algae growth in my systems for the last year. The iron is from the pipes we have here in my neighborhood. TRhey are cast iron and starting to break as they age. There is not a day in the summer where the city does not have a crew fixing another break in the mains. Not sure what has been clogging the R/O membranes, but it could be calcium, magnesium or phosphate, or all three. I am so tired of buying membranes that I decided that a softner was the ticket.
Now, what you saw in the growth of your softies could be a results of a needed trace element that was being taken out of the water by your R/O unit. My guess would be iron or iodine, but who knows. Soft corals are known to grow really well on tidal mudflats subject to fresh water runoff from the land and other unpristine reef conditions and locations. Same with Mushrooms. My Softie system is doing awesome as well. I will see if there is a difference when I switch back to R/O.
Continued good luck!
Brad]