I've fished nymphs with my Tenkara rod, but do not use indicators. With Tenkara I can feel the take much easier than with my Western fly rod. I also use an orange level line that I purchased from Chris Stewart. The line in itself acts as an indicator. If you feel you need to use an indicator I would use a foam stick on Pulsa. I would think anything heavier would hinder your casting. As far as furled tenkara lines go, you may want to look at Moon Lit Fly Fishing. Just make sure you get a bright color as they are easier to see.