Chaeto dying

[cubbyman60]

Hey all,
Over the last week, almost all of my chaeto has started turning white and becoming brittle. I posted two pictures: initially after first adding the chaeto and another just to show it was growing- it eventually grew much bigger very rapidly, but I don't have any pictures. I removed a lot of it the dead portions, and it continues to die off. Still have high nitrates (about 20) and algae growing in the sump. Any idea why it died? No major tank changes.
I was wondering two things: too much light. Sometimes I keep the plant light on for up to 15 hours. Or, is Iron depleted? Let me know what you think.

Thank you.

 

[Diesel]

What were the NO3's and Po4's while you had the chaeto growing?
It could be iron but the level of iron in a saltwater system is already higher than NSW which is around 0.0006 mark.

 

[MaiReef]

Cheato dies when the Nitrates get really low if the light intensity stays high(in my experience).

 

[cubbyman60]

Thanks for the responses.
The nitrates initially were about 30-40. Now, they're about 25. (Salifert.) I do not have a phosphate kit.

How long do you run your lights?

 

[cubbyman60]

bump anyone?

 

[lion king]

Yes I have notice shrinking chaeto with too much light and/or low iron. Low nutrients also but yours are plenty.