I wouldn't worry about it. What you are looking at is probably beneficial for your tank. I noticed that your tank (as mine) is quite newly set. It shall take us another six to eight months to realize if our tanks will end up with a steady algae problem.
Check the following pic of diatoms forming an algae-like structure in an isolated "pool" I took in the Caribbean coast of Hispaniola Island, where I live. If your tank ends up looking like this, then check your nitrates and
phosphate levels, if higher than expected, you know what to do: go with small but frequent water changes.
Pepetj
Santo Domingo