Why is my frogspawn doing this?

[seandre3000]

Noticed lastnight my frogspawn had a bubble in the center. It’s back to normal today. What was it doing?

 

[Timfish]

It's not very clear but why corals "bubble" or "bounce" is up in the air. Light spectrum is a factor though.

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0097018

 

[kevgib67]

I haven’t seen with my torches but a big bubble appears on my hammers and frogspawn when they are beginning to split.

 

[vetteguy53081]

Noticed lastnight my frogspawn had a bubble in the center. It’s back to normal today. What was it doing?

My hammers do this occasionally when fed or over fed and also ive seen this more than once when there is lack of flow. Torches do best mid-tank or above opposed to lower part of tank where there is less PAR and flow