tell me about polyp extension

[afex]

i'm relatively new to keeping acropora. (kept montipora and anacropora in my first tank)

i recently got 3 frags from upscales (birdsnest, stag, samoensis) and i've noticed that the stag only has decent PE when the lights are out. during the "day" it's PE is minimal at best. but when i wake up in the morning to go to work (tank lights have been off ~8 hrs), with the room lights on i can see that the stag has great PE.

why is that? i thought the polyps came out while the lights were on. the birdsnest and samoensis have good PE while the lights are on. the corals are sitting together on a frag rack on the sand bed.

when i first saw the stag had poor PE i thought maybe it needed to be higher in the tank or needed better water quality than the other 2, but once i saw it at night, i just dont know what to think.

thanks for any advice!

 

[twon8]

most acros will have better pe at night,

 

[bboats]

I notice this too, I think it depends on the acro.

 

[afex]

<a href=showthread.php?s=&postid=8003239#post8003239 target=_blank>Originally posted</a> by twon8
most acros will have better pe at night,

do you know why that is?

 

[twon8]

because in nature they feed predominately at night

 

[miwoodar]

Borneman mentioned in his book that many corals might actually be trainable to show more polyp extension by feeding them during the daylight hours. If only I my yellow tang weren't so greedy I would have a better shot at this.

 

[Obi-dad]

afex, what fish do you have in the tank? Some fish cause poor PE, notably clown gobies and some pygmy angels. I would never ever have another clown goby in my tank due to this.

 

[afex]

currently i have a lawnmower blenny and a sailfin tang.

haven't seen either picking at the frags.