Frag Tank versus Display

[ca1ore]

OK, I have a small frag tank plumbed into my system. Both frag tank and display use the same LED lighting. Frags in FT show very good polyp extension, but when I put them into the display they show much less. I run the lights at a much higher level in the DT so I assume this is the reason since they both have the same water and similar flow. Any opinions on this?

 

[tripdad]

Your an old hand at this reef thing so I'm sure you have thought about the fish in the display? I had a coral beauty and NEVER saw it nip but somehow I think the corals can sense a predator is nearby. I had lousy PE until I removed him, Then was great PE. You've hit the others, flow and lights. The only other thing is the flow can sometimes look the same or be the same equipment but due to other corals placement or structures it can be very different, sounds like you've tried different corals and different spots, same results everywhere?

 

[ca1ore]

Thanks for the the thoughtful reply. I really don't think its a fish (though I suppose it could be) as I haven't had any observed nipping at all. I think it's probably the main LEDs.

 

[Pife]

How does the polyp extension compare at night?

 

[ssscuz]

Surely nutrient levels, flow, lighting, bioload etc are different between tanks.
I doubt that polyp extension will be from to much light.

 

[Mael]

I have always been curious with coral polyps if the slight pressure difference of being in a shallow tank vs deeper or lower in a tank vs higher would cause any difference in polyp extension and "stretching"

MY RDA zoas stretched to twice their height due to low light in the corner they were in, so again this could be it as the lower light lvl in the frag tank makes them stretch or extend a bit more. Same thing happened to an xfactor monti, had better and longer polyp extension than when in lower light.

 

[Peter Eichler]

Thanks for the the thoughtful reply. I really don't think its a fish (though I suppose it could be) as I haven't had any observed nipping at all. I think it's probably the main LEDs.

Fish can be sneaky about it and even the occasional nip is enough to keep polyps from fully coming out. I just had a genicanthus that would nip mayve once out of every 4-5 hours of tank viewing. It's enough to make extension different between my display and frag tank.