Algae? "White slime" bacteria?

[Gobi-Wan]

Hi all. My aquarium is about 7 weeks past cycling and I am noticing something clear, very long and stringy growing in my refugium. It seems to be mostly concentrated in the center where the grow lamp is focused. It is growing off of my chaeto as well as straight out of the sand and rocks where the light hits. I can't really find anything online that looks quite like what I have. Nothing in the display tank or sump yet just in the refugium. I have chaeto and caulerpa in the refugium... I don't know if that's a bad idea? But I planned to see which does better in my fuge.

 

[Gobi-Wan]

Sorry I just realized I didn't really include any helpful information. 75g display, 20g sump, 10g refugium. My nitrates are 10 phosphate <.25 and have been very stable around that, as I have been adding fish. In fact nitrates have been slightly dropping between water changes. As of now I have cut the flow off to the fuge and cranked up my skimmer a little. I had it flowing very slowly, maybe only 100gph. Is that too slow for a refugium? Wondering if that could have anything to do with growing undesirables... I am trying to grow pods and didn't want to blast them through the fuge all at once.