Zoas stretch for reasons other than lighting?

CorbetJackson50 · Apr 16, 2018

I have a zoa dominated 25g lagoon tank 12" deep. Lit with a Kessil A360we. Intensity and color both max out at 50% during the day for 2 hrs. I don't think low light is to blame for the stretched out stalks on a few of my zoas. I have around 50 different zoas and there are only 4-5 that are doing this. I ramped the light intensity up to 90% and color to 75% over the course of a couple weeks. The only difference I noticed was more algae growth. I am doing 20% weekly water changes with Red Sea Coral Pro Salt.

saltyfilmfolks · Apr 16, 2018

IMO. Some have long stalks.

When I moved stretched for Light palys it took 3-4 weeks or more till they went back to shape.

Beyond that I have only seen higher flow do that.

CorbetJackson50 · Apr 17, 2018

saltyfilmfolks said:
IMO. Some have long stalks.

When I moved stretched for Light palys it took 3-4 weeks or more till they went back to shape.

Beyond that I have only seen higher flow do that.

I do have pretty high flow... maybe I’ll dial it down some.

slayerhellfire · Apr 20, 2018

whats your nutrients at like po4 and nitrates?

CoralGuy19 · Apr 20, 2018

It could just be that they have longer stalks. I thought the same thing about a few of mine and then realized that they just had longer stems

CorbetJackson50 · Apr 21, 2018

Nitrates hover between 5-10ppm phosphates I haven’t checked but would assume they are within acceptable range???

When I got them they did not have long stalks like this...

CorbetJackson50 · Apr 21, 2018

I have come up with a theory possibly. The tank lights don’t come on until around noon, they all open up and stretch towards the window/ambient light. I wonder if the low light morning period is causing this maybe?

OriginalUserName · Apr 23, 2018

That light on a 12" deep tank should be giving them plenty of par if it's on 100% intensity.

CorbetJackson50 · Apr 24, 2018

OriginalUserName said:
That light on a 12" deep tank should be giving them plenty of par if it's on 100% intensity.

I agree! It should be plenty even at 50%. I’m currently maxed at 75% for 4 hours at peak

fishgirljockey · Oct 26, 2022

CorbetJackson50 said:
I do have pretty high flow... maybe I’ll dial it down some.

When flow is strong, Zoas shrink short to sort of hide from the flow. If you have calm water, they get comfortable and stretch out long. The stem has nothing to do with lighting. The petals are what tell you if it needs more light. If they are stretchEd up making a cup shape, then it needs more light. If the petals are flush with the center, the lighting is perfect.