Hi guys this is my first post here. Started Cycling my opae ula tank yesterday.

- aquarium sand
- rain water with reef salt at 1.01 salinity
- marimo balls
- coral chips
- hydrilla plant

when I flooded the tank, I noticed white fuzzy patches against the walls. Using a toothpick these can be scraped off. What are these stuff and do I leave them there? Help.....
https://ibb.co/t3TSDkyhttps://ibb.co/4jzjwL8