Refugium help please

[Gobi-Wan]

Ok so I built a custom stand for a 75g many years ago, and only recently decided to make it a reef tank. So long story short, in order to fit what I wanted inside the stand (it has center braces) I made the refugium a separate 10G tank. I control the flow with a split return from the sump. The setup is a little over 4 months old and everything is very stable. Nitrates and phosphates are very low all the time. However, I can't seem to get the refugium to stabilize. Every time I start running the light 12+ hours for the chaeto, the whole fuge starts developing nasty slime all over, especially the chaeto. The first time it happened was definitely dynos (brown snot rockets with a bubble in the end), I went lights out in the fuge for a week or so and it was fine. Never showed up in the DT. However I am starting to get small patches of cyano in the DT so onviously the chaeto isn't growing like it should. Second time i started over with chaeto it's this nasty green slime coating everything the light touches. Pretty sure its gonna kill the chaeto. The light in running is a "thinklux" par36 grow light from Amazon. Is this what's causing the problems? I also added a small 100gph pump to the chaeto area and that didn't help at all. Should I try adding a baffle and making a separate area without sand so the chaeto can tumble? I want to keep the sand and rubble for pods so I don't want to go completely bare bottom in the fuge. Any suggestions would be appreciated.

 

[Fritzhamer]

Try doing less than a 12 hour light cycle. It might take a bit of time to find the sweet spot here. I run 12 hours a day on mine but I had to step back to a "weak" light to find my sweet spot. I run a kessil A80 Sun light, the freshwater light. I tried all of their horticultural lights as well some of the horticultural Amazon led lights. For me the freshwater light is spot on. I do get a patch of hair algae or cyano now and again but I just remove it and let it take it's course. Usually the appearance of those guys lets me know that its time to prune back some of my macro algae.

 

[Gobi-Wan]

Try doing less than a 12 hour light cycle. It might take a bit of time to find the sweet spot here. I run 12 hours a day on mine but I had to step back to a "weak" light to find my sweet spot. I run a kessil A80 Sun light, the freshwater light. I tried all of their horticultural lights as well some of the horticultural Amazon led lights. For me the freshwater light is spot on. I do get a patch of hair algae or cyano now and again but I just remove it and let it take it's course. Usually the appearance of those guys lets me know that its time to prune back some of my macro algae.

Thank you. I will try tinkering some more. It's hard getting advice on a forum when you have DIY custom stuff. Experiences seem to vary wildly.

 

[lapin]

I have a separate fuge. It grows slime on the glass. Its full of red macro algaes. Rock rubble and reborn calcium media. No chaeto. The reds do fine. Greens not so fine. Red / blue / white grow light. 11 hour light cycle. When the slime covers the glass, pods bloom and eat it away in about a week. Goes in cycles this way. I have some small Florida Nerite snails in there to help.