I've used this before. It didn't bother any of my plants. That said, if this is the one that turns your tank slightly blue you want to keep something in mind. Always do at least a 25 percent water change before every new dose. This prevents toxicity from building up.
Secondly keep in mind how the Ich parasite works. Ich goes through a life cycle that has three distinct phases. Phase one is usually when it is first introduced to your tank and when you first really notice it. Often it is already burrowed into your fish's slime coat. At this point it is nearly immune to any treatment. It is using the slime coat to protect it. In severe cases fish will actually shed their slime coat as an attempt to rid themselves of the parasite.
Eventually the parasite will drop off of the fish. It will sink, and turn into something kind of like a dormant stage. It goes through division, and at this point can only be removed/targeted by regular gravel vacuuming, stirring the substrate up, and doing water changes. You want to lesson how many pop up and go into the next stage. This stage that comes is the free swimming. It is now susceptible to heat, and medication. So it swims around to find a host, burrows in, and then starts all over.
One stage can be hit, the other two are nearly immune. This is what makes it so difficult to eradicate. Your best solution is to keep up with your treatment for at least 1-2 weeks. Keep up with daily water changes, daily gravel vacuuming (and vacuum decor). Scrub your walls before your water changes. Keep a look out for the condition of your fish. When the flashing stops, the rubbing, the twitching, and you see no more physical signs of Ich on your fish....continue the treatment for at least 2 more days.