Sunny D's haven't grown a new polyp in over a year!

[Mummy Dust]

Hello, I've had a frag of sunny d's for about 2 years now and they have completely ceased to grow new polyps. They initially were growing just fine, doubling the number of polyps. They look fine to my eye but I could definitely use some input. Water parameters are excellent. I wouldn't be asking otherwise! Anyone have any advice? A pic for your perusal:

 

[Robert_ellis]

Look to be stretching a bit. Hit them with more light.

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[bshow24]

They should still grow even with some stretching. When you say excellent, what do you mean exactly? Zoas tend to like a bit "dirtier" water than say, SPS. Having some nutrients is always best.

 

[Mummy Dust]

Thank you all for your responses. I believe the problem was lighting. I have one last question. How much light do yellow brick road zoas prefer? I have them next to a colony of fruit loops that have grown like mad. Thanks again.