SPS on Frag Rack

Trenton Henderson · Jul 23, 2023

I have a new monti-cap frag and a green slimer frag that is bleaching slightly at the base on a frag rack in the lower half of the tank. I just added the green slimer to it because it was bleaching a bit as of this afternoon.

The frag rack sits below the powerhead, but that doesn’t provide a ton of flow, especially not for SPS. Do I need to position them in a way they get more flow, or is the light acclimation more important? I would think that as people bring the frags from the bottom of the tank up when acclimating, the flow is pretty low.

Acros · Jul 23, 2023

Usually, in SPS dominated systems there are very few areas with low flow.

I don’t believe SPS needs light acclimated unless you are going to put them in 400+ par.

Trenton Henderson · Jul 23, 2023

Acros said:
Usually, in SPS dominated systems there are very few areas with low flow.

I don’t believe SPS needs light acclimated unless you are going to put them in 400+ par.

My tank was dimmer than I thought, so shortly after adding the slimer frag, I adjusted the lights such that the spot it was in went from about 170 PAR to 220 PAR and I extended the photoperiod by about an hour. It came from higher PAR, so I can’t figure out why it didn’t respond well to that. I’ve put it on the rack to help it recover.

Acros · Jul 23, 2023

Are there other SPS doing well in the tank?

Trenton Henderson · Jul 23, 2023

Acros said:
Are there other SPS doing well in the tank?

That was really the first one. There was one other birds nest frag that STN’ed I think because my alkalinity was a lot higher than the LFS. Could have been the same for this frag. The monti cap seems to be doing well though.

Acros · Jul 23, 2023

Sounds like the tank is not ready acros yet. How old is the tank? What are your parameters? I would focus on getting the parameters stable.

Acros · Jul 23, 2023

220 par is on the lower end for acros.

Trenton Henderson · Jul 23, 2023

Acros said:
Sounds like the tank is not ready acros yet. How old is the tank? What are your parameters? I would focus on getting the parameters stable.

Alk: 9 dKH
Ca: 430-440 ppm
Mg: 1350-1400 ppm
pH: 8.1-8.2
Nitrate: 5-10 ppm
Phosphate: 0.03-0.05

Alkalinity was high because I added some dry rock to the aquascape. It went up and I’ve been bringing it back to 9 dKH slowly. It was about 9.8 dKH. Tank has been running for 9 months.

Acros · Jul 23, 2023

Trenton Henderson said:
Alk: 9 dKH
Ca: 430-440 ppm
Mg: 1350-1400 ppm
pH: 8.1-8.2
Nitrate: 5-10 ppm
Phosphate: 0.03-0.05

Alkalinity was high because I added some dry rock to the aquascape. It went up and I’ve been bringing it back to 9 dKH slowly. It was about 9.8 dKH. Tank has been running for 9 months.

The parameter are fine. What are the tank dimensions and what kind of light do you use?

Trenton Henderson · Jul 23, 2023

Acros said:
The parameter are fine. What are the tank dimensions and what kind of light do you use?

It’s a Marineland 60 gallon long (very narrow and pretty deep). I have two Kessil A360X’s currently at 94% intensity, but will be ramping them up after I lengthen my photoperiod to 9 hours or so. My photoperiod was only 5 hours before. It’s now 6, but I’m waiting a couple weeks before extending it more. I’m only doing SPS very high in the tank, where the PAR is at or above 200 PAR.

Acros · Jul 23, 2023

It is going to be a challenge growing acros under the two kessils with those dimensions.

If you have good coraline algae growth, you could try adding acros. When doing so, add directly under the light, just don’t bother with the frag racks.

What par meter do you use?

Trenton Henderson · Jul 23, 2023

Acros said:
It is going to be a challenge growing acros under the two kessils with those dimensions.

If you have good coraline algae growth, you could try adding acros. When doing so, add directly under the light, just don’t bother with the frag racks.

What par meter do you use?

Coralline is growing well. I placed it directly under the light. PAR meter is the USB Smart Quantum SQ-420X by Apogee.

What do you suppose could have been the issue with the green slimer? You make it sound that it’s not light related. Could it be alkalinity instability? Are acros sensitive to pH swings?

Acros · Jul 23, 2023

I can’t see anything wrong other than newish tank and low par. Everything else looks good.

9 months is more than enough time if you started with live rock.

Trenton Henderson · Jul 23, 2023

Acros said:
I can’t see anything wrong other than newish tank and low par. Everything else looks good.

9 months is more than enough time if you started with live rock.

I started dry. My tank destroys nutrients. I have to dose phosphates and nitrates to keep up at times.

If it were you, would you leave the acro where it was, or would you bring it down for recovery where it’s not getting hit by as much light?

Acros · Jul 23, 2023

I would leave it where they are or move to higher light.

Trenton Henderson · Jul 23, 2023

Acros said:
I would leave it where they are or move to higher light.

Come to think of it, my phosphate dropped to 0.01 and I had to dose it back up. Could that be a culprit?

Acros · Jul 23, 2023

I wouldn't think so. You will get dinos from low phosphates, before it kills sps. It sounds to me that your tank just needs more time to mature.

christwendt · Jul 23, 2023

Trenton Henderson said:
Come to think of it, my phosphate dropped to 0.01 and I had to dose it back up. Could that be a culprit?

That’s pretty low. With the plus or minus deviation of digital phosphate checkers that could be zero phosphate in reality. I had issues with acros when my phosphate would ever drop below like 0.03.

christwendt · Jul 23, 2023

Acros said:
I wouldn't think so. You will get dinos from low phosphates, before it kills sps. It sounds to me that your tank just needs more time to mature.

Personally when I had dinos it took a few weeks for them to settle in when it was reading zero nitrate and phosphate. I didn’t have sps at the time but If that happened now they would definitely suffer if not die if I bottomed our nutrients for that low.

teethdoctor23 · Jul 24, 2023

I’ve noticed a few things, starting from dry rock to being able to grow SPS and acros. Firstly I feel that your lighting and flow needs to match, high light and high flow. Also your nutrients should be relative to your Alk. What that means is if you’re having trouble keeping your nutrients consistent but you’re running a higher alkalinity, acros will tend to grow skeleton faster than they can create tissue which will lead to burnt tips potentially and then subsequent algae growth, for example. What helped me get over the hump was correct placement in the tank, managing my Alk level to achieve great stability, boosting my pH from 7.8 to 8.3, and then lastly, I began dosing Brightwell Microbacter 7 daily, along with phytoplankton. Yes, acros do better in a mature system, but that’s usually because of a couple things: stability and bacteria. The bacterial strains that are present in successful, stable reef tanks are much different than new tanks. If you can seed some of those bacterial species into your tank and then maintain good, stable water chemistry, there’s no reason you can’t keep acros with proper lighting and flow.