Polyp size shrinks

[GeoHawk]

I wondered if there is a general idea on what makes polyps shrink. I have zoas in my display tank that have nice size polyps, when I place them in my frag tank they shrink down over several months, still in good health and growing new polyps like in my display. My display tank is lit with 1 250 wat MH and 2 T5s that are both about 8 inches of the water, zoas usually 20 inches deep. My frag tank is lit by 4 T5 fixture that is on mounting legs about 2 inches off the water, zoas usually 9 inches deep. My theory is higher light smaller polyps, but I wanted other opinions. Also my tanks aren't plumbed together so parameters are a little different. I have fish in both tanks. I think I am going to raise the T5 over my frag tank up and see what affect it has.

Any ideas out there??????????

 

[PRomero]

I've always wondered this as well, I would like to increase the polyp size. I know with lower light they stretch to reach the light but in my tank the polyps stay small still lol.

 

[Aqua fire/medic]

I've seen this as well, although it's usually different lighting set ups that do this. LED's seem to make the polyps bigger in size while T5/MH make them smaller. Interesting/weird

 

[PRomero]

Very true on the lighting, I'm thinking it may also have something to do with the color temperature. The more blue the smaller the polyps or vice versa.

 

[3Dsam]

Very true on the lighting, I'm thinking it may also have something to do with the color temperature. The more blue the smaller the polyps or vice versa.

+1

i recently changed my lighting spectrum (without replacing any of the lights) so i have more blue with less white. Needless to say some of my zoas and palys polyps have shrunk:/

 

[dougers31]

All of my zoas are smaller than their original size, whether it's in my frag tank or my display. Both are lit by T5's.

 

[joshporksandwich]

Every tank is different. In my experience polyps were huge under mh with reefbrites. With leds my zoas got smaller. But i have friends that with leds their zoas are huge and also with t5 lol. I say be happy your corals grow and remember every tank is different. What works for me might not work for you.

 

[PRomero]

To add another twist to the riddle, I recently replaced a blue plus t5 with an actinic t5 to my frag tank and after a few days all my zoas have a cup shape to them lol, it's really wierd. Current lighting in my frag tank is ati coral plus t5, 24-blue leds, ati actinic t5. I'm thinking I'll experiment with a 6500k t5 bulb next for the extra Par, maybe it'll bring out brighter colors from my zoas.

Joshporksandwich is somewhat correct, if your zoas are happy and growing then you shouldn't worry. However if one drops a lot of money (most of these zoas are very expensive) on a coral it's because they like the way it looks, Not so cool when it morphs or changes when you put it in your system.

I'm thinking the white spectrum is what needs to be tweaked. Maybe, have the whites on for most of the day and turn on the blues when you want to view the tank, for the extra pop, then go back to the heavy ugly white/yellow lights so your zoas grow the way they should. I'm gonna try that next but if the results are inconclusive then it may just be something in the water :/.

 

[duke4130]

If the whites are too strong and on for too long of a period, the polyps will shrink. I run a radion so it is easy to dim the bulbs. Too much light in general will cause the shrinking issue. What are the run times on your lights? I have noticed having peak day for only 2 hours and not 4-6 hours like I used to have them will help make the polyps want to spread out and be larger. Hope this helps

 

[PRomero]

If the whites are too strong and on for too long of a period, the polyps will shrink. I run a radion so it is easy to dim the bulbs. Too much light in general will cause the shrinking issue. What are the run times on your lights? I have noticed having peak day for only 2 hours and not 4-6 hours like I used to have them will help make the polyps want to spread out and be larger. Hope this helps

That's exactly what I was thinking, just do a short burst of high par white light for a couple of hours, I have yet to try this on my system as I"m all T5 + blue led but plan to incorporate this in my future light build. Hopefully this will yield larger polyps. I run the actinics/blue's for 12hrs and whites for 8hrs.