I logged in after being off for a couple hours, and when I looked at my Iron Storage, it was down by about 600,000. I had not chosen to upgrade anything in my stronghold, and the only thing I was crafting was 1 Harpoon when I left. The harpoon was complete, but my Iron Storage had gone down significantly. How do I get my Iron Storage back?
Are you talking about your Iron or the Iron Storage capacity? Because as far as I know storage buildings cannot be converted to other buildings, so there is no way of decreasing iron capacity. If you are talking about iron stored or accumulated, maybe you put some emblems on some heroes.
Raid losses? That’s a lot, but 3 people took nearly 100k in iron from me.
Any chance you emblemed some hero? This uses food and iron, and the required amounts are huge especially for higher 5* levels.
Being raided you can only lose food and iron accumulated in the watchtower.