I totally get the appeal of copper sulfate for a quick fix, but I’ve always worried about what it does downstream—like, literally. Even small amounts can end up in groundwater or local streams, and that stuff isn’t great for fish or plants. What’s worked for me is a combo of regular snaking and planting root barriers (or just keeping thirsty trees far from the lines). It’s more work upfront, but I sleep better knowing I’m not adding chemicals to the mix. Not saying it’s perfect, but it feels like a safer bet long-term.
I hear you on the copper sulfate—my plumber swears by it, but I just can’t bring myself to dump that stuff down the drain. I tried root barriers once, but the maple in my yard laughed and sent roots right under them. Ended up digging a trench and rerouting the line... not fun, but at least now I don’t have to worry about surprise indoor waterfalls every spring. Sometimes I think trees are just out to get us.