Nutrients / Lighting Relationship?

[BigAsh]

Is anyone aware of a relationship between nutrients and lighting intensity (par)? My nutrients increased a little and my acro tips went brown. Then STN set in from the top down and algae took over the skeleton. This happened on about 15 acro frags/colonies all at the same time over the course of a couple months. Only a couple acros were not affected and only a few are hanging on for dear life. I don't have a par or light meter (should probably get one) but could this be caused by too much light in combination with elevated nutrients?

Nutrient levels increased from undetectable (acros doing great) to 8 ppm NO3 and 30 ppb P. I'm using an ATI PowerModule with 8-54w t5 about 9" above the water surface. Acros are at least 6" below the water surface.

Thoughts? Thanks!

 

[Ocelaris]

Usually corals are pretty tolerant of the nutrients (nitrates and phosphates) changing, but not so much with alkalinity. What's your alkalinity at, and how often do you test? Lighting can play a part, but usually once you meet the needs and aren't bleaching things, I'd review the stability of alkalinity and any other swings you can account for. Especially if the lights haven't changed, you can rule them out.

I test every other day lately, but when I was struggling, I'd test all 4 every day for a few weeks till I got a handle on algae and everything else.

 

[BigAsh]

Thanks for the reply. I was checking Alk daily until I thought I had my dosing dialed in. It seemed fairly stable at 8.3 to 8.7. Then I started testing weekly. When the brown tips happened, I checked Alk and it had climbed to about 9.3. I didn't think that would be enough to brown all those tips but maybe that was it. I also noticed that the blades on my Gyres were covered in algae and the flow had slowed down. Maybe the low flow and Alk increase caused the problem.

 

[saltyfilmfolks]

I think it more likely it was the restricted flow. And the tips may have been "suffocated " you have to eyeball that. (I turkey baster the rocks pretty frequently and watch the "dust blow ".


For the origainal question.
https://www.reef2reef.com/threads/h...d-i-dont-know-what-to-do.210035/#post-2401666

https://www.reef2reef.com/threads/light-alkalinity-nutrients.319223/