Zoa getting dull and smaller, but continue to grow

dkorenieva · Dec 5, 2023

Hi there,

I have Fluval evo 13.5g tank started at the end of September. Haven’t replaced light or filtration. I have introduced multiple Zoa and Duncan coral in mid October. Then hammers in November and few corals in December.
Zoa corals seemed to be doing well for a month or so. But then I noticed Zoa becoming duller and duller. Some have shrienked. Though they continue to grow small heads. What can be the problem with them?

Current inhabitants:
2 hermit crabs
Trochus snail, astrea snail, cerith snail, bumblebee snail
1 clownfish
1 shark nose goby
1 rock flower anemone
1 Duncan coral
2 hammer corals (seem to be the most thriving of the corals now)
1 micromussa
1 acan bowerbanki
1 acan lord
Big piece of Chaeto

My water parameters:
NO2 = 0
NO3 = 0
pH = 8.3
kH = 8.0 - 8.7
Ca = 360
Mg = 1010
PO4 = 0
Salinity = 1.025-1.026
Temp = 26C

I’ve got tests for Ca and Mg just couple of days ago, so started to raise these parameters slowly. Alkalinity fluctuates through the week: highest after water change and then falls each day.
I dose 5ml of all-for-reef everyday (started recently as well)
Chaeto grows really nicely now. Introduced copepods as well

Attached photos of zoa

Timfish · Dec 5, 2023

Your PO4 is low. Corals store phospholipids for a rainy day. Once it's used up they run the risk of bleaching as their zooxanthellae scavenge for what little phosphorus might be available.

FWIW .03 mg/l is the threshold level to prevent phosphorus limitation in corals, identified by researchers at Southampton University in England using corals maintained in an aquarium for about a decade. .3 mg/l is what corals are subjected to with upwelling in the ocean. .5 mg/l might be acceptable for some as acros have been shown to increase growth up to this level. .9mg/l is the level the Steinhart Aqaurium's ex situ sexually reproduced acro colonies are being grwon out with. Rich Ross's (who's part of the team at Steinhart) has his acro dominate mixed reef sitting at 1.8 mg/l, his tank can be seen at the beginning of his MACNA presentation on phosphate. You can see his current levels as well as some cool videos of corals spawning in his thread.

Rich Ross - Home Tank - guess the phosphate

This tank was built before r2r, here is a link to some links about the build. http://packedhead.net/home-reef/ Current test results: 03-17-2017 Ammonia (NH3-4) Good 0 0.000 - 0.050 mg/L 03-17-2017 Nitrite (NO2) Good 0.006 0.000 - 0.100 mg/L 03-17-2017 Phosphate...

www.reef2reef.com

Mr. Mojo Rising · Dec 5, 2023

In addition to above, turn you lights up a little if you can. The zoa's seem to be reaching up and browning out a little.

Salty_Northerner · Dec 5, 2023

Unfortunately that light as is, isn't the best for growing coral. I had the same issue till I bought a better light and got my phosphate in line then they started to perk up and color back up. Add in your AFR is a good start for sure! Also get that mag level up around 1300-1400, AFR wont add enough mag to bring it up. What salt are you using?

dkorenieva · Dec 5, 2023

How to increase PO4 level? I feed more than fish can eat and plenty of food is left on the sand for crabs to finish. But heavy feeding doesn’t increase anything in the tank.
Would dosing Brightwell Aquatics NeoPhos or Seachem flourish phosphorus solve the problem? https://www.jlaquatics.com/additives/brightwell-aquatics-neophos-500ml.html

Should I decrease amount of Chaeto as well?

kevgib67 · Dec 5, 2023

Ya, nitrates are zero as well as phosphates, they are starving. Need to get both up.

Reefkeepers Archive · Dec 5, 2023

Timfish said:
Your PO4 is low. Corals store phospholipids for a rainy day. Once it's used up they run the risk of bleaching as their zooxanthellae scavenge for what little phosphorus might be available.

FWIW .03 mg/l is the threshold level to prevent phosphorus limitation in corals, identified by researchers at Southampton University in England using corals maintained in an aquarium for about a decade. .3 mg/l is what corals are subjected to with upwelling in the ocean. .5 mg/l might be acceptable for some as acros have been shown to increase growth up to this level. .9mg/l is the level the Steinhart Aqaurium's ex situ sexually reproduced acro colonies are being grwon out with. Rich Ross's (who's part of the team at Steinhart) has his acro dominate mixed reef sitting at 1.8 mg/l, his tank can be seen at the beginning of his MACNA presentation on phosphate. You can see his current levels as well as some cool videos of corals spawning in his thread.

Rich Ross - Home Tank - guess the phosphate

This tank was built before r2r, here is a link to some links about the build. http://packedhead.net/home-reef/ Current test results: 03-17-2017 Ammonia (NH3-4) Good 0 0.000 - 0.050 mg/L 03-17-2017 Nitrite (NO2) Good 0.006 0.000 - 0.100 mg/L 03-17-2017 Phosphate...

www.reef2reef.com

Well that helps me out! My po4 is currently at the threshold level for a week or so, I've been trying to up feedings though even with one cube a day it's stayed the same (coral only setup) well I guess that's a sign my makeshift hair algae refeugium is working a little too well lol

Timfish · Dec 6, 2023

FWIW I wouldn't use an algae scrubber. As you noticed algae competes with corals for nutrients but algae also dumps Dissolved Organic Compounds, DOC, into the water that can have direct and indirect effects on corals. Sinc e cryptic sponges are excellent for removing labile DOC (includiong types that can't be removed with skimmers or GAC) and are essential recyclers I would pull the algae and turn off the lights and add some live rock rubble for the sponges to grow on. Here's some links if you want on DOC and sponges:

"Coral Reefs in the Microbial Seas" This video compliments Rohwer's book of the same title (Paper back is ~$20, Kindle is ~$10), both deal with the conflicting roles of the different types of DOC in reef ecosystems. While there is overlap bewteen his book and the video both have information not covered by the other and together give a broader view of the complex relationships found in reef ecosystems

Changing Seas - Mysterious Microbes

BActeria and Sponges

Maintenance of Coral Reef Health (refferences at the end)

Indirect effects of algae on coral: algae‐mediated, microbe‐induced coral mortality

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onlinelibrary.wiley.com

Influence of coral and algal exudates on microbially mediated reef metabolism.
Coral DOC improves oxygen (autotrophy), algae DOC reduces oxygen (heterotrophy).

Influence of coral and algal exudates on microbially mediated reef metabolism

Benthic primary producers in tropical reef ecosystems can alter biogeochemical cycling and microbial processes in the surrounding seawater. In order to quantify these influences, we measured rates of photosynthesis, respiration, and dissolved organic carbon (DOC) exudate release by the dominant...

peerj.com

Role of elevated organic carbon levels and microbial activity in coral mortality

http://www.int-res.com/articles/meps2006/314/m314p119.pdf

Effects of Coral Reef Benthic Primary Producers on Dissolved Organic Carbon and Microbial Activity
Algae releases significantly more DOC into the water than coral.

Effects of Coral Reef Benthic Primary Producers on Dissolved Organic Carbon and Microbial Activity

Benthic primary producers in marine ecosystems may significantly alter biogeochemical cycling and microbial processes in their surrounding environment. To examine these interactions, we studied dissolved organic matter release by dominant benthic taxa and subsequent microbial remineralization in...

journals.plos.org

Pathologies and mortality rates caused by organic carbon and nutrient stressors in three Caribbean coral species.
DOC caused coral death but not high nitrates, phosphates or ammonium.

http://www.int-res.com/articles/meps2005/294/m294p173.pdf

Visualization of oxygen distribution patterns caused by coral and algae

Planar optodes were used to visualize oxygen distribution patterns associated with a coral reef associated green algae (Chaetomorpha sp.) and a hermatypic coral (Favia sp.) separately, as standalone organisms, and placed in close proximity mimicking coral-algal interactions. Oxygen patterns were...

peerj.com

Biological oxygen demand optode analysis of coral reef-associated microbial communities exposed to algal exudates
Exposure to exudates derived from turf algae stimulated higher oxygen drawdown by the coral-associated bacteria.

Biological oxygen demand optode analysis of coral reef-associated microbial communities exposed to algal exudates

Algae-derived dissolved organic matter has been hypothesized to induce mortality of reef building corals. One proposed killing mechanism is a zone of hypoxia created by rapidly growing microbes. To investigate this hypothesis, biological oxygen demand ...

www.ncbi.nlm.nih.gov

Microbial ecology: Algae feed a shift on coral reefs

Microbial ecology: Algae feed a shift on coral reefs - Nature Microbiology

Human pressures on coral reefs are giving macroalgae a competitive advantage over reef-building corals. These algae support larger, and potentially pathogenic, microbial populations that are metabolically primed for less-efficient, yet faster, carbohydrate remineralization, perpetuating a...

www.nature.com

Coral and macroalgal exudates vary in neutral sugar composition and differentially enrich reef bacterioplankton lineages.

Coral and macroalgal exudates vary in neutral sugar composition and differentially enrich reef bacterioplankton lineages - PubMed

Increasing algal cover on tropical reefs worldwide may be maintained through feedbacks whereby algae outcompete coral by altering microbial activity. We hypothesized that algae and coral release compositionally distinct exudates that differentially alter bacterioplankton growth and community...

www.ncbi.nlm.nih.gov

Sugar enrichment provides evidence for a role of nitrogen fixation in coral bleaching

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onlinelibrary.wiley.com

Elevated ammonium delays the impairment of the coral-dinoflagellate symbiosis during labile carbon pollution
(here's an argument for maintaining heavy fish loads if you're carbon dosing)

Elevated ammonium delays the impairment of the coral-dinoflagellate symbiosis during labile carbon pollution

Labile dissolved organic carbon (DOC) is a major pollutant in coastal marine environments affected by anthropogenic impacts, and may significantly con…

www.sciencedirect.com

Excess labile carbon promotes the expression of virulence factors in coral reef bacterioplankton

Excess labile carbon promotes the expression of virulence factors in coral reef bacterioplankton - The ISME Journal

Coastal pollution and algal cover are increasing on many coral reefs, resulting in higher dissolved organic carbon (DOC) concentrations. High DOC concentrations strongly affect microbial activity in reef waters and select for copiotrophic, often potentially virulent microbial populations. High...

www.nature.com

Unseen players shape benthic competition on coral reefs.

Unseen players shape benthic competition on coral reefs - PubMed

Recent work has shown that hydrophilic and hydrophobic organic matter (OM) from algae disrupts the function of the coral holobiont and promotes the invasion of opportunistic pathogens, leading to coral morbidity and mortality. Here we refer to these dynamics as the (3)DAM [dissolved organic...

www.ncbi.nlm.nih.gov

Allelochemicals Produced by Brown Macroalgae of the Lobophora Genus Are Active against Coral Larvae and Associated Bacteria, Supporting Pathogenic Shifts to Vibrio Dominance.

Allelochemicals Produced by Brown Macroalgae of the Lobophora Genus Are Active against Coral Larvae and Associated Bacteria, Supporting Pathogenic Shifts to Vibrio Dominance - PubMed

Diverse microbial communities associate with coral tissues and mucus, providing important protective and nutritional services, but once disturbed, the microbial equilibrium may shift from a beneficial state to one that is detrimental or pathogenic. Macroalgae (e.g., seaweeds) can physically and...

www.ncbi.nlm.nih.gov

Macroalgae decrease growth and alter microbial community structure of the reef-building coral, Porites astreoides.

Macroalgae decrease growth and alter microbial community structure of the reef-building coral, Porites astreoides - PubMed

With the continued and unprecedented decline of coral reefs worldwide, evaluating the factors that contribute to coral demise is of critical importance. As coral cover declines, macroalgae are becoming more common on tropical reefs. Interactions between these macroalgae and corals may alter the...

www.ncbi.nlm.nih.gov

Macroalgal extracts induce bacterial assemblage shifts and sublethal tissue stress in Caribbean corals.

Macroalgal extracts induce bacterial assemblage shifts and sublethal tissue stress in Caribbean corals - PubMed

Benthic macroalgae can be abundant on present-day coral reefs, especially where rates of herbivory are low and/or dissolved nutrients are high. This study investigated the impact of macroalgal extracts on both coral-associated bacterial assemblages and sublethal stress response of corals. Crude...

www.ncbi.nlm.nih.gov

Biophysical and physiological processes causing oxygen loss from coral reefs.

https://elifesciences.org/articles/49114.pdf

Global microbialization of coral reefs (coral decline correlates with increased algae and DOC)

Global microbialization of coral reefs - Nature Microbiology

Analysis of 60 sites in three ocean basins suggests that overgrowth of fleshy algae on coral reefs supports higher microbial abundances dominated by copiotrophic, potentially pathogenic bacteria via the provision of dissolved inorganic carbon.

www.nature.com