Acans very slowly thinning.

[ryanuy]

Hi!

Ive been running a frag tank for about 8 months. Everything was okay until fairly recently I've noticed some LPS especially some of my acans and a bowerbankii slowly thinning out. At night they still have they polyps extended and still have a pretty decent feeding response. I feel like something is stressing them but I dont know what it could be. The tank is very lightly stocked. Only 1 black tang, 1 naso tang, and 1 rabbitfish. It is a 200g system.

Its a mixed frag tank with LPS, zoas, and sps. The SPS and soft corals are all doing okay. They're all growing well. The problem is only with some of the LPS which seem to be very slowly but very surely thinning out. The tissue of the coral doesnt seem to be receding yet but it seems like its thinning out.

I have other LPS in the tank like hammers and torches and brains and they all seem to be doing okay.

The tanks parameters are the following:

Cal - 420
Alk - 6.8 - 7
SG - 1.025
Nitrates - 10
P04 - .03

I did an ICP test last month and there wasnt anything abnormal with it.

I run an oversized skimmer. I have GAC and GFO in bags in the sump. I have a fairly large refugium with chaeto only. I don't dose any carbon.

For lights, i use the Maxspect ethereal. One of my friends told me that maybe i was setting them too high so I've lowered them by 30% a few days ago and hopefully that helps as well. He also said that maybe the flow was a bit high so i moved them to areas in the tank with the lowest flow.

I was wondering maybe the alk is a bit too low? Would that be the cause of this?

Any help or input would be appreciated!

Thank you!

 

[Mal11224]

It's hard to pinpoint what the issue could be. Could be lighting. But I see your Alk is a little low for the amount of nitrates in your tank. I like to see higher alkalinity with nitrates of 10ppm.

 

[ryanuy]

It's hard to pinpoint what the issue could be. Could be lighting. But I see your Alk is a little low for the amount of nitrates in your tank. I like to see higher alkalinity with nitrates of 10ppm.

Yup! Im dosing more alk slowly actually. I will be trying to bring it up to 8 dkh in a few days. I started dosing a bit more today and will continue to monitor it. It just seems like theres something stressing these guys out but i really cant pinpoint what it is.

 

[Starblenny]

Do you feed your acans & bower?

 

[ryanuy]

Do you feed your acans & bower?

I feed Red Sea Reef Energy A and B 3x a week at night. I also feed the soft corals reef roids but i disperse it in the tank so i think they probably are able to get some of it? Today ive started target feeding mysis to the thinner ones especially.

 

[NY_Caveman]

Have a picture? Is it possible the Hammers / Torches are close enough (5-6 inches) to the Acans to sting them? Those Euphyllia can be aggressive.

EDIT: Thinning though, as opposed to tissue damage may make this less likely. Zoas also with chemical warfare if they are upstream of the Acans could be possible.