Switched to LEDS, weird algae growth

I can't tell unless I see pics but I had a friend who might had the same problem and she ended up having something called "Calothrix, a type of cyano. Calothrix is the name of a genus, but in the hobby it refers to brown slime cyanobacteria that have some filamentous features. That is pretty much what you have there. If it were a little longer or redder is would fall under "Lyngbya", but it usually isn't worth taking microscopic shots of the particular cyano to get an accurate species level identification. "(John Maloney)

 

Sounds great ReefBruh, I will keep an eye on things thanks very much!

 

Just like all the other blooms in your tank... it'll exhaust whatever resource it's using and then it'll sort of reign itself in. In the mean time, manual removal is a must. Make sure you're using RODI or you'll just keep feeding it nutrients.

 

Or you could run some GFO to help combat the yucky stuff in the tap water