Green Star Polyp not spreading

[sleeri]

I've had a medium sized rock full of green star polyps for about 3 months now. The polyps are doing great. They're full & vibrant, but they aren't spreading. Does anything in particular prohibit their ability to spread (or encourage it)? I currently don't dose iodine. Does/could this play a role? I've always gone on the assumption that water changes are enough to provide reef nutrients such as iodine.
Thanks for any help you can give me.

 

[thegrog]

Iodine really doesn't matter with polyps spreading. You are right in that regular water changes replaces it.
I would look at your alkalinity and calcium levels. If they are low, the polyps won't spread.
It could also be as simple as not having enough random currents hitting them. They like lots of random water flows. Mine did not spread much until I changed the water flow around and now I can't get them so stop growing!

 

[darknes]

One way to get them to spread is to cut out a chunk and glue it to another rock. The chunk you cut out will soon fill in, and the new rock will spread quickly.
Also, as TheGrog mentioned, calcium and alkalinity, and water movement could be an issue as well.

 

[sleeri]

Thanks for the help TheGrog.
I drip kalk. The last time I tested calc was at 420-430. I thought calc wasn't as critical for softies?
I may have to look into the water current suggestion. Although, I think I'll give it another month or so before I start tinkering.