Actinics and algae

[2bafish]

Yes checked them again. Fine. Maybe the algae is using up the nitrates and that's why it's reading fine. I reduced my light schedule to 9 hours and shut of my moonlights at night. Maybe it helps. Also got a sea hare

[sphelps]

Well the purple bulb probably has red in it which tends to spike things up a little but blue also plays a large role in plant growth, plants mostly only use blue and red spectrum so increasing either of these can result in more algae growth.