Getting growth and color but no polyps on acros

[Ssteve]

Slowly moving towards a more sps dominated tank, and most things are doing well as far as color and growth, but I have two acros that I don't get much polyp extension on. I have four small birdsnests that all have grown and gotten really good color out of and three are nice thick and fuzzy looking and another one basically has no polyps but has grown really quickly. I've been dosing small amounts of Brightwell nano code a and b but only testing calc and mag. Salt is aquavitro salinity.

No no2/3, ammonia etc. 7dkh and no phosphates.

 

[chad7531]

While this isn't the cause of your polyp problem, you aren't testing for the most important thing, alkalinity.

 

[Ssteve]

Sorry, didn't post it. 7dkh

 

[jda]

Some acros just don't ever have good PE.

With otherwise good PE type of corals, most of the time, low PE is a sign of a fish picking on them, pests (red bugs), or out of whack tank parameters.

Pictures might help.

Off topic, but you should be dry mixing your Salinity if you don't already.

 

[Ssteve]

Like rolling the bucket? I do that. My fish don't pick at them but I have a yellow clown goby who likes to purch on them.

 

[jda]

You are set if you roll the bucket - just wanted to make sure... that salt settles as bad as any that I have ever seen.

Clown Gobies are pretty bad polyp nippers. Search it out. Actually, gobies in general will eat 'em some polyps most of the time.

 

[Ssteve]

I've had the goby a long time and he sticks mostly to the birdsnest which seem fine. It's the acros I'd really like to see polyp up and he's never even on that side of the tank.

 

[dieselkeeper]

Can you try moving the coral to a different location? Are they glued down? Different flow and/or lighting might make a difference. I think any fish can nip corals. All the books and online state that all tangs are "with caution" in a reef.

 

[Tek]

Is PE out at night?

 

[Ssteve]

yeah they come out some at night when I feed

 

[jda]

At night is usually when the nippers will nip, since that is when the polyps are out. Seriously, like 90% chance your goby is nipping on them, or some other fish.

 

[Ssteve]

The only reason i don't think that's the case is cause I had several tanks and for a while the only thing in with my sps's were my clowns and they didn't extend still, then for a while it was my cherub and clown goby and they didn't extend. Now the only thing added is a tang that came with this tank in which case the previous owner didn't have polyp issues and had a lot more fish(8-10) than I currently do. So unless its all of my fish who nip than I think its more to do with water or lights. I have recently changed to kessils and am hopeful its a acclimation thing as I started the lights low and have been ramping them up but started to bleach a acro so I think I jumped the gun too much.

 

[Tek]

Most fish nip during the day as they rest at night. I had little PE on acros and milles and it was due to my flame angel. The same coral has full PE day and night now after it was removed.

The other reason would be too much carbon or GFO stripping the tank, or lights with the wrong spectrum/PAR.

 

[M88A2]

I had a yellow clown goby that would sit on a slimmer mini colony and pick at it every once in a while. It was still a bright green but the polyps were always retracted. once I got rid of the yellow clown goby the polyps came out after 2-3 days