What would you do?

[ElementReefer]

I have had various soft and LPS coral in my tank now for 16 months. Started with all dry rock. There’s plenty of coralline, tube worm colonies, pineapple sponges, etc, to indicate relative stability.

I put in a few “beginner” SPS 5 weeks ago: a Monti Spongodes, Monti Digitata, and Green Slimer Acro. They are all holding on, but not growing. I know coral take time to settle in, but a pattern has emerged that I can’t explain:

I do a 10-20% WC weekly. For the first few days, the SPS look happy. As the week goes on, polyps start to retract and tissue starts to degrade in spots from the tips down. The next water change happens, and they act happy again for a few days. By mid-week they subtly start to decline again. Every week they get a tiny bit worse.

I would blame swings in N and P, but testing does not support it. N runs 5-10, P runs 0.03 to 0.1. Alk, Cal and Mag are kept stable by a doser. It’s like water changes are magic, but I don’t like magic. I am not sure what to test or change.

Theories: Volatile organics that the skimmer isn’t removing? pH? Low trace elements?

PAR ~200 (For now)
Alk 8.3
Cal 420
Mag 1400
Flow moderate to strong
Salt: Tropic Marin Pro Reef
Internal skimmer
HOB with floss for water polishing

 

[ElementReefer]

 

[KrisReef]

ICP test to see if there are funky elements that don’t belong, that a magic water change briefly gives the coral hope for better days?

Edit:
Now that the pictures are posted, I would add a polyfilter to attack chemical ware fare from the softies? Easier and cheaper to try first.

Corals look ok!

 

[neonreef3d]

the only bottle neck that i can see that may hinder growth may be the 200 PAR your running.. and perhaps the lack of bio diversity a live rock can introduce.

My 100 gallon suffered the same symptoms until I added some live rock and a refugium to manage nutrient levels.

 

[ReefGeezer]

Two things stand out:
1. 200 PAR is low for most SPS; and
2. You never mentioned the stability of your alkalinity.

 

[Charlie’s Frags]

Alk stability doesn’t matter. Just keep in a 7-8 range for your lower Po4. 0.10-0.15 po4 would be better. Looks like a typical case of over stripping the water to me. I would start by getting rid of the filter floss and see what happens.

 

[Rick5]

P runs 0.03 to 0.1.

How quickly does your tank fluctuate between .03 and .1?

 

[ElementReefer]

How quickly does your tank fluctuate between .03 and .1?

This is not straightforward to answer because the precision of the Hanna is +/- 0.04.

 

[ElementReefer]

Alk stability doesn’t matter. Just keep in a 7-8 range for your lower Po4. 0.10-0.15 po4 would be better. Looks like a typical case of over stripping the water to me. I would start by getting rid of the filter floss and see what happens.

That’s the question though, if Po4 is too low (especially for Alk 8.5) then why do the coral look better after a water change?

 

[Charlie’s Frags]

That’s the question though, if Po4 is too low (especially for Alk 8.5) then why do the coral look better after a water change?

Wc’s don’t reduce much of any po4 ime. Maybe you’re adding something that’s irritating them and the wc dilutes the pollutant but you have creeping tissue recession and wc’s are not going to be able to help for much longer.
What all are you dosing and feeding?

 

[ElementReefer]

Wc’s don’t reduce much of any po4 ime. Maybe you’re adding something that’s irritating them and the wc dilutes the pollutant but you have creeping tissue recession and wc’s are not going to be able to help for much longer.
What all are you dosing and feeding?

Here are all the details. Feel free to recommend changes to any of this, it’s my first tank and I see it all as an experiment.

55 gallon long, no sump, age 16 months
8 fish (one is a Foxface, the rest smaller)
AquaticLife 30 Gal internal skimmer, cup fills every 2-3 days
Seachem Tidal 35 running floss, change weekly
Nicrew LED 100W x2, running 50% blue 10% white, 1-8-1 schedule
2x Jebao power heads at ~40x tank turnover per hour

Seachem two part dosed by RedSea doser 4x daily
1/2 cube Hikari frozen, morning
1 cube Hikari frozen OR LRS Frenzy, evening
1/2 TSP reef Roids broadcast 3x weekly
10% WC weekly, on average

 

[Charlie’s Frags]

Here are all the details. Feel free to recommend changes to any of this, it’s my first tank and I see it all as an experiment.

55 gallon long, no sump, age 16 months
8 fish (one is a Foxface, the rest smaller)
AquaticLife 30 Gal internal skimmer, cup fills every 2-3 days
Seachem Tidal 35 running floss, change weekly
Nicrew LED 100W x2, running 50% blue 10% white, 1-8-1 schedule
2x Jebao power heads at ~40x tank turnover per hour

Seachem two part dosed by RedSea doser 4x daily
1/2 cube Hikari frozen, morning
1 cube Hikari frozen OR LRS Frenzy, evening
1/2 TSP reef Roids broadcast 3x weekly
10% WC weekly, on average

Did you test par with a par meter or are you guessing? I have the nicrew 100w on a 7g 12” cube frag tank and it set at 100%blue and 30% to get 400 par with my apogee 510 meter

 

[ElementReefer]

Apogee 210.

At current settings, PAR 200 at mid tank under each light, 100 on sandbed. In the middle of the tank is a lower light area at PAR 125 where I keep some LPS. No rocks higher than mid tank.

Light positions shown, inside at top of canopy.

 

[Tired]

Edit:
Now that the pictures are posted, I would add a polyfilter to attack chemical ware fare from the softies? Easier and cheaper to try first.

What soft corals do you have? This seems a likely suspect, particularly if you have any sort of leathers.

 

[ElementReefer]

What soft corals do you have? This seems a likely suspect, particularly if you have any sort of leathers.

All that’s left in this tank is a small green Kenya tree. Took the Sinularia sp out months ago. The other softies are zoas, gsp and a couple anemones.