Just wondering if anyone has isolated a specific cause that makes ropes pick up aluminum dirt quickly. The last two new ropes I've had have both gotten lots of black aluminum residue on them within the first weekend of their use, and I've been trying to figure out exactly what the culprit is. I've tried different anchor draws, but that didn't help. I'm thinking ATC or Grigri. Anyone else have this problem or have any suggestions for keeping a new rope clean longer?