GFO shocking Corals?

I'm not sure exactly where to post this, as I have soft, sps, and lps, but I thought I'd start here. Over the last couple months, I've been stocking my tank with new corals. This one was set up in May of this year, and since I set it up, I've been using GFO in my carbon/GFO reactor. I started using it in my previous 35 gal and didn't see much of a difference. The last coral I added to that tank was a green goniopora and within a week, I noticed it starting to expand less. Moving back to the 75 gal. When I transferred everything from my 35 to my 75, Goni barely opened at all. I got a toadstool mushroom coral, same thing. Looked great for a week, then stopped expanding, constantly shriveled up. Next, got a plate coral. Same thing, but it didn't even last a week before it started shrinking. I was very confused as to why these corals looked so amazing at the lfs, but started withering when I put them in my tank at home. It took a hell of a lot of research before I came even close to locating the problem. BRS GFO. Not only was I using the recommended dose they said to use, which is waay too much, the new corals I've been adding to my tank were being sucepted to high levels of it from the moment they entered my tank, whereas my lfs doesn't use GFO. This stresses them out and causes them to shrink and stay that way. Someone correct me if I'm wrong, but I'm certain GFO is the culprit. Has anyone else had an experience similar to this? What are some safer alternatives to BRS GFO? How long does it take for corals to recover from something like this?