Chaeto is Shrinking, not enough Nutrients?

Lol sorry i was joking!! I probably should have added a smiley face in there or something!!!

 

It's common for macro algae to become nutrient limited. Often iron is the limiting nutrient and many people do dose Iron to keep their macro algae going.

Randy Holmes-Farley discuses Iron here:
Chemistry And The Aquarium: Iron In A Reef Tank — Advanced Aquarist | Aquarist Magazine and Blog

Also, sometimes other nutrients such as nitrate or phosphate can become limiting. People will sometimes dose nitrate, in the form of KN03 (potasium-nitrate) in order to reduce phosphate further, if there macro algae is nitrate limited, and there is still phosphate. The reverse, phosphate limitation when nitrate there is still nitrate, also occurs and some people do dose phosphate in this situation. However, these are getting more advanced, as careful monitoring and measurement is required.

Iron is fairly safe to dose however, and if you read a bit about it, such as Randy's article, I don't see any issue with doing so. I tend to think if there is a nitrate limitation, it's easier to just run some GFO though. And I personally would never dose phosphate as test kits just aren't accurate enough to detect the extremely low levels we would like to see in our systems (<.03ppm).

 

Wow interesting!! Think chaeto would die because its overgrown/not spinning? Mine is either dying because of that, perfect params, or this new 24 hour fuge lighting i've been trying out, although many people do it successfully.. I hope its perfect params !!!