Who Gives A Fish Forums

I had a crazy growth spurt with my vallisneria about 5 months ago - it was sending out new runners every week. I ended up with too many, so I trimmed it back, but I only cut where the runners were coming out, not the leaves. Now it's been 4 months and I haven't seen any new growth - no new runners at all. I've been using seachem iron, excel, and flourish like I always do, so I'm not sure what's going on. My nitrates are stable at around 30ppm and my ph is 6.8.

It's possible your vallisneria just went through a growth spurt and now it's in a resting phase. Vallisneria typically has periods of intense growth followed by a period of recovery. When you trimmed the runners, it might have triggered this recovery phase and now it's focusing on rebuilding its energy reserves.