Tank has been up with about 1/2 established rock, half new Marco rock. Sand is new too. About 6 weeks old. This stuff is growing on the new rock and sand wherever the light shines. What kind of algae is this? .03 phos 2.3 nitrate
looks straightforward cycle bloom of things like diatoms and perhaps a bit of green hair type. The new rock caused a change in balance somewhat. Wouldnt concern me , just test nutes and do a decent water change if the nitrates have spiked too much