Balancing Nutrients for Coral Growth/Health Instead of Nuisance Algae

[LiftinTheVeil]

I've found myself in a paradox of Coral Health and Nuisance Algae Growth!

I have a 130-gallon LPS dominant tank which has been setup for about a year and four months (first reef tank). It's been thriving for about three months now and I've seen really great coral growth and PE during this time. Whereas before everything was relatively stalled and PE was not great.
I contribute this largely to the fact that I've been feeding the fish a bit more and also dosing phyto and aminos. About two months ago I overdid it by feeding ReefBlizzard in excess and have since been paying the price in the form of GHA. I am running a medium/large (~1ft x 1ft x 2ft) fuge in the sump using a Tunze 8831 (12hr light cycle). The entire time my NO3 has been undetectable (RedSea Kit). PO4 has been all over the place, once at 0.26ppm and recently 0.04ppm (ULR Hanna). I believe the PO4 has been changing wildly because I have been removing GHA weekly. After it is removed, I see PO4 raise and as the GHA takes hold again it drops.

Since the battle with GHA algae, I've been feeding less and reduced amino and phyto dosing. As a result, PO4 has dropped and it seems coral PE is reduced and growth has slowed again.

Last parameter record (3/9/2022):
Alkalinity: 9.12 dKH
Calcium: 415 ppm
Magnesium: 1396 ppm
Salinity: 35.1 ppt
Ammonia: 0 ppm
Nitrites: 0 ppm
Nitrates: 0 ppm (Almost always undetectable using RedSea kit)
Phosphates: 0.04 ppm (When PO4 was higher coral PE and growth was great)
Temp: 78.0F
pH: 8.05

I have been recently reading about many of the common methods of phosphate export to get rid of the GHA once and for all, but I keep landing at the same question(s):

• SHORT TERM: I'd like to reduce nutrients low enough to kill off the GHA, but understand I will also have an effect on corals. What can be done to remove GHA, but keep the coral happy?
• LONG TERM: How do I balance nutrients available in the system to promote coral growth and overall health while avoiding nuisance algae?
• What is the best way to identify having "enough" nutrients in the system for coral health if the nutrients are undetectable? Whether this is due to coral or algae consumption or both.

I'd really like to hear what you all have done to rid your DT of nuisance algae while keeping your coral happy!
Also, for those that don't currently have an algae issue, what do you think contributed to your success in providing the right nutrient demand for your coral while keeping unwanted algae to a minimum?

This is my first post here and want to thank all of you on the R2R forums! It's been a great tool over the last year and really enjoy the conversations.
It's great to have so much friendly conversation about the hobby all in one place.

 

[Drummingbaker2010]

Emerald crabs, yellow tangs and lawnmower blennies are all good candidates that will eat that stuff as well as scraping it and removing it through water changes. I don't know if you have any of these, but they will feast on it helping to keep it under control.

 

[Drummingbaker2010]

Emerald crabs, yellow tangs and lawnmower blennies are all good candidates that will eat that stuff as well as scraping it and removing it through water changes. I don't know if you have any of these, but they will feast on it helping to keep it under control. My situation was maybe a little unorthidox because I had to run through the nitrification cycle of my tank with some cown fish and some pre-existing animals in it, but I think the best thing is to get a pretty diverse clean up crew that will munch on the algae as it starts growing to keep it under control.

 

[Drummingbaker2010]

for long term control, I would maybe start by dosing weekly, and check the parameters shortly before dosing again to see how much has actually been consumed by your corals. It is better start little by little and test until you determine when is the best time to dose again. You might also think about raising your ph a little bit more to 8.3-8.4.

 

[LiftinTheVeil]

Emerald crabs, yellow tangs and lawnmower blennies are all good candidates that will eat that stuff as well as scraping it and removing it through water changes. I don't know if you have any of these, but they will feast on it helping to keep it under control.

Thank you for bringing that up, I forgot to mention stock. Regarding those that eat algae, I do have two emerald crabs, a yellow tang, a powder brown, a hippo, several hermits, a pincushion urchin and a lawmower blenny in my QT as we speak. I do manual removal and WC just about every week and I must say it has gotten a little better in terms of the amount of regrowth.

I do admit I am lacking in the snail department as I probably have about 10 astreas at the moment.

 

[LiftinTheVeil]

for long term control, I would maybe start by dosing weekly, and check the parameters shortly before dosing again to see how much has actually been consumed by your corals. It is better start little by little and test until you determine when is the best time to dose again. You might also think about raising your ph a little bit more to 8.3-8.4.

Are you referring to dosing aminos?
Yes I'd like to get the pH up eventually. I do dose alk with soda ash so that and the fuge definitely helps, but it does need a little boost.

 

[SPS2020]

Following along...same boat and similar process of getting the GHA, but with Acropora dominant 100g. It is a balance that we have to learn with N03 and PO4. Pellet foods are higher in PO4 and frozen are higher in NO3. I had been at 0 ppb PO4 (Hanna ULR) for over a year and stopped checking...UNTIL GHA started popping up all over. I have a yellow and bristletooth tang who do not touch the GHA. TONS of snails who cannot be bothered with it and two tuxedo urchins that would rather eat everything else. I have the PO4 in check (too low at present) and NO3 at .25. Lots of sea lettuce in the fuge. So far, I've been doing manual removal and hope the levels are such that everything else will starve it out eventually. It will take time for it to go away just as it took time for it to get to the current state.

BRS has a good video out recently worth watching: BRStv Master Series: Nitrate & Phosphate

 

[mdb_talon]

My goal is always to have some nutrients in there. I feed very heavy and have a ton of export. Sometimes my nitrates and phosphates bottom out to 0, but generally I keep them 5-15 and .05-.15. I do get algae that grows and I wont trade what I consider best for the coral (heavy feedings) in order to have an algae free tank. So I also have a large cleanup crew and for the most part they do a great job of keeping the algae in check and recycling those nutrients. I find urchins and abalones are by far best algae removers for me.

 

[LiftinTheVeil]

Following along...same boat and similar process of getting the GHA, but with Acropora dominant 100g. It is a balance that we have to learn with N03 and PO4. Pellet foods are higher in PO4 and frozen are higher in NO3. I had been at 0 ppb PO4 (Hanna ULR) for over a year and stopped checking...UNTIL GHA started popping up all over. I have a yellow and bristletooth tang who do not touch the GHA. TONS of snails who cannot be bothered with it and two tuxedo urchins that would rather eat everything else. I have the PO4 in check (too low at present) and NO3 at .25. Lots of sea lettuce in the fuge. So far, I've been doing manual removal and hope the levels are such that everything else will starve it out eventually. It will take time for it to go away just as it took time for it to get to the current state.

BRS has a good video out recently worth watching: BRStv Master Series: Nitrate & Phosphate

I am definitely learning... just don't have that balance yet! Like you, I don't expect it to go away quickly as I've been battling this for two months now. I am happy to do it (sorta :/) as I know its the only way. Still interested in hearing responses to hopefully provide some knowledge on approaches that have had success with this balance!

 

[LiftinTheVeil]

My goal is always to have some nutrients in there. I feed very heavy and have a ton of export. Sometimes my nitrates and phosphates bottom out to 0, but generally I keep them 5-15 and .05-.15. I do get algae that grows and I wont trade what I consider best for the coral (heavy feedings) in order to have an algae free tank. So I also have a large cleanup crew and for the most part they do a great job of keeping the algae in check and recycling those nutrients. I find urchins and abalones are by far best algae removers for me.

Thanks for the info! Do you mind sharing your tank size and the export methods? Also how much are you feeding?
I'd really love to get to a point where I can feed and export heavy, but I am having trouble ramping up to that point without either over-feeding or over-exporting.

Edit: I'm also with you on sacrificing an algae-free tank for good coral health. Just don't want the lush grass takeover!

 

[Hans-Werner]

My philosophy regarding these nutrients is very simple:

Phosphate is for corals, nitrate is for algae.

I'm convinced it has something to do with calcification of corals (and the algae we like) and access of algae we hate to phosphates deposited in rocks and gravel, which corals don't have. So these algae just need nitrate or another nitrogen compound and it is nearly impossible to starve them out with phosphate removal, at least not without harming the corals even much more.

I recommend not to remove phosphate except absolutely necessary which means 0.5 ppm phosphate or higher.

 

[Subsea]

My philosophy regarding these nutrients is very simple:

Phosphate is for corals, nitrate is for algae.

I'm convinced it has something to do with calcification of corals (and the algae we like) and access of algae we hate to phosphates deposited in rocks and gravel, which corals don't have. So these algae just need nitrate or another nitrogen compound and it is nearly impossible to starve them out with phosphate removal, at least not without harming the corals even much more.

I recommend not to remove phosphate except absolutely necessary which means 0.5 ppm phosphate or higher.

I add ammonia to encourage desirable competition.

 

[MaxTremors]

Thank you for bringing that up, I forgot to mention stock. Regarding those that eat algae, I do have two emerald crabs, a yellow tang, a powder brown, a hippo, several hermits, a pincushion urchin and a lawmower blenny in my QT as we speak. I do manual removal and WC just about every week and I must say it has gotten a little better in terms of the amount of regrowth.

I do admit I am lacking in the snail department as I probably have about 10 astreas at the moment.

You need 85-125 snails for a tank that size (depending on rockwork). A variety of species (turbo, astrea, trochus, nerite, cerith, etc). And 60-90 small hermits, and 15-30 nassarius snails. Also a fighting conch or two. People always vastly under stock their CuC. I wouldn’t add them all at once, slowly increase their numbers over a couple months.

 

[Hans-Werner]

Low ammonium concentrations have no negative effects to corals, which makes them better than nitrate (although nitrate rarely every has negative effects because it just isn't the only nitrogen compound available to the corals), but it increases the need for phosphate.

One more thing that is good to know is that the molar concentrations of nitrogen compounds and of phosphate corals need to have any net uptake are about the same. They are around 0.2 µM for phosphate and similar for ammonium, nitrate, urea and amino acids, which means for example 0.02 ppm phosphate, 0.004 ppm ammonium or 0.013 ppm for nitrate.

Effects of nitrate concentrations of say 10 ppm are not based on any needs of corals for N but maybe on an inhibition of iron reduction or something the like.

 

[DxMarinefish]

I neglected my 250 gallon mixed reef last year due to family illness and over time the balance went off resulting in GHA bloom.
I also had my pump feeding my 2x ATS die off and clossed-loop pump fail as well, so all in all a bad situation for the tank.

What I did was fix my failed pumps so my 2x ATS were fully operational and increase flow with the Closedloop back online.
I restarted my Sump Refugium with my H380 light, which I lit 24/7 for 3 months.

I also restocked my snails and Urchins. For snails I have found over the years that True Mexican Turbo snails will attack GHA of al size/length.
Because of the stringy nature of the GHA, most other snails won't eat the GHA once its 2cm or more.

I massively increased my Urchin population, focusing on Tuxedo Urchins. I currently have 5, with 3 more to come.

I also ironically increase my Phyto feeding. Reason is that I wanted the other micro-herbivours like copepod, amphipods, etc to increase, and boy have they increased in number. This has meant that these little busy critters have attacked the GHA before it can increase in size/length, while Urchins and Snails attack the larger GHA.

Other snails include what @MaxTremors has listed. You need mouths to stir the sand and eat uo all the uneaten food before they rot and release nutrients back into the water. I also have 1x fighting conch, 1x Tiger tail cucumber.


Within 3 months my GHA just melted from the DT.

My new challenge now is Aiptasia. Lots of peppermint shrimps that just ignore them. I can't get a Aiptasia eating filefish or

 

[Timfish]

Couple things to point out. Consider the possibility you've already fixed the problem and if you just stay the course with what you're doing the nuisance algae will just dissappear on it's own. Much like when a system is set up there's a sequence of events as the system cycles and matures, a stress event, like over feeding or dosing mixups (too much as well as not enough) or environental disruptions will cause a series of cycles, meybe severe or maybe mild.

Nitriate and phosphate are only small parts of the picture. When we consider nutrient cycling, in terms of total C, N and P, we need to consider (even though we can't test) particulate forms and organic forms as well as inorganic forms. Abbreviations you'll see are, for carbon - DOC, POC and DIC; for nitrogen - DON, PON and DIN; for phosphate - DOP, POP and DIP. Some of these forms may be preffered over others. For corals the organic nitrogen in the forms of urea and amino acids are preffered over the inorganic forms of ammonia and nitrate. (Nitrate is corals least preffered form of nitrogen and research has shown it can have a detrimental effect on coral calcification.)

What steps or changes did you make in hte weeks or month or two before you're tank started looking good? Those are likely the changes that helped. If you made a change a week before everything started looking "good" it's likely not the primary reason (nad might actually be detrimental to some extent). Feeding prepared coral food is particularly suspect from what I've read. I'll list them below but all the research I've found shows very species specific responses and even "goldilocks" response in a species.

Anyway, all that is to say carefully consider everything you've done and everything that has happened over tha last 6 months or so before making changes that might be more harmful than helpful.

WHat I didn't touch on was all the microbial stuff that's going on so here's some refferences that explain it much better than I can and some additional links. But first a couple pics:

Fig 4 from Phosphorus metabolism of reef organisms with algal symbionts



Fig. 3 from Context Dependant Effects of Nutrient Loading on the Coral-Algal Mutualism


Papers on feeding corals:

Coral farming: effects of light, water motion and artificial foods

Improved coral cultivation will facilitate the reduction of wild harvesting, reef restoration, preservation of biodiversity, and the use of corals as model experimental organisms. In this study, we examine species-specific responses in growth and

www.academia.edu

Comparing the capacity of five different dietary treatments to optimise growth and nutritional composition in two scleractinian corals

Developing an optimal heterotrophic feeding regime has the potential to improve captive coral growth and health. This study evaluated the efficacy of three exogenous diets: Artemia nauplii (ART), a commercially available coral diet (Reef Roids) (RR), and a novel, micro-bound diet (ATF), against...

journals.plos.org

Elucidating an optimal diet for captive Acropora corals

Developing an optimal heterotrophic feeding regime has the potential to improve the growth and overall health of captive corals. This study evaluated …

www.sciencedirect.com

Influence of different feeding regimes on the survival, growth, and biochemical composition of Acropora coral recruits

Heterotrophic feeding in newly-settled coral planulae can potentially improve survivorship and accelerate early development in some species; however, an optimal diet to facilitate this does not currently exist. This study evaluated the efficacy of three heterotrophic feeding regimes (enriched...

journals.plos.org

"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


Nitrogen cycling in hte coral holobiont


BActeria and Sponges


Maintenance of Coral Reef Health (refferences at the end)


Optical Feedback Loop in Colorful Coral Bleaching


Richard Ross What's up with phosphate"

 

[LiftinTheVeil]

My philosophy regarding these nutrients is very simple:

Phosphate is for corals, nitrate is for algae.

I'm convinced it has something to do with calcification of corals (and the algae we like) and access of algae we hate to phosphates deposited in rocks and gravel, which corals don't have. So these algae just need nitrate or another nitrogen compound and it is nearly impossible to starve them out with phosphate removal, at least not without harming the corals even much more.

I recommend not to remove phosphate except absolutely necessary which means 0.5 ppm phosphate or higher.

That makes sense to me! In my case I do have a fuge running relatively well at the moment and my nitrates are always undetectable. Is there something else that I can do to help limit unwanted algaes?

I like your philosophy and wont implement PO4 exports at this time.

You need 85-125 snails for a tank that size (depending on rockwork). A variety of species (turbo, astrea, trochus, nerite, cerith, etc). And 60-90 small hermits, and 15-30 nassarius snails. Also a fighting conch or two. People always vastly under stock their CuC. I wouldn’t add them all at once, slowly increase their numbers over a couple months.

I completely agree I do need to up the CUC as I had a bit of a snail die-off. Now that I am thinking about it, it was around the same time the GHA was at its worst. Maybe a coincidence, probably not. I do have some nassarius snails left and a fighting conch.
What hermits do you recommend? The hermits I picked up at my LFS when my tank was newish loved to hunt and kill the snails.

I neglected my 250 gallon mixed reef last year due to family illness and over time the balance went off resulting in GHA bloom.
I also had my pump feeding my 2x ATS die off and clossed-loop pump fail as well, so all in all a bad situation for the tank.

What I did was fix my failed pumps so my 2x ATS were fully operational and increase flow with the Closedloop back online.
I restarted my Sump Refugium with my H380 light, which I lit 24/7 for 3 months.

I also restocked my snails and Urchins. For snails I have found over the years that True Mexican Turbo snails will attack GHA of al size/length.
Because of the stringy nature of the GHA, most other snails won't eat the GHA once its 2cm or more.

I massively increased my Urchin population, focusing on Tuxedo Urchins. I currently have 5, with 3 more to come.

I also ironically increase my Phyto feeding. Reason is that I wanted the other micro-herbivours like copepod, amphipods, etc to increase, and boy have they increased in number. This has meant that these little busy critters have attacked the GHA before it can increase in size/length, while Urchins and Snails attack the larger GHA.

Other snails include what @MaxTremors has listed. You need mouths to stir the sand and eat uo all the uneaten food before they rot and release nutrients back into the water. I also have 1x fighting conch, 1x Tiger tail cucumber.


Within 3 months my GHA just melted from the DT.

My new challenge now is Aiptasia. Lots of peppermint shrimps that just ignore them. I can't get a Aiptasia eating filefish or

Well it sounds like I'll be taking a trip to my LFS this weekend to start introducing new CUC.
On a side note, I am also dealing with aiptasia and after doing loads of research, I think I am going to pull the trigger on some Berghias if it gets any worse.

 

[LiftinTheVeil]

Couple things to point out. Consider the possibility you've already fixed the problem and if you just stay the course with what you're doing the nuisance algae will just dissappear on it's own. Much like when a system is set up there's a sequence of events as the system cycles and matures, a stress event, like over feeding or dosing mixups (too much as well as not enough) or environental disruptions will cause a series of cycles, meybe severe or maybe mild.

Nitriate and phosphate are only small parts of the picture. When we consider nutrient cycling, in terms of total C, N and P, we need to consider (even though we can't test) particulate forms and organic forms as well as inorganic forms. Abbreviations you'll see are, for carbon - DOC, POC and DIC; for nitrogen - DON, PON and DIN; for phosphate - DOP, POP and DIP. Some of these forms may be preffered over others. For corals the organic nitrogen in the forms of urea and amino acids are preffered over the inorganic forms of ammonia and nitrate. (Nitrate is corals least preffered form of nitrogen and research has shown it can have a detrimental effect on coral calcification.)

What steps or changes did you make in hte weeks or month or two before you're tank started looking good? Those are likely the changes that helped. If you made a change a week before everything started looking "good" it's likely not the primary reason (nad might actually be detrimental to some extent). Feeding prepared coral food is particularly suspect from what I've read. I'll list them below but all the research I've found shows very species specific responses and even "goldilocks" response in a species.

Anyway, all that is to say carefully consider everything you've done and everything that has happened over tha last 6 months or so before making changes that might be more harmful than helpful.

WHat I didn't touch on was all the microbial stuff that's going on so here's some refferences that explain it much better than I can and some additional links. But first a couple pics:

Fig 4 from Phosphorus metabolism of reef organisms with algal symbionts



Fig. 3 from Context Dependant Effects of Nutrient Loading on the Coral-Algal Mutualism


Papers on feeding corals:

Coral farming: effects of light, water motion and artificial foods

Improved coral cultivation will facilitate the reduction of wild harvesting, reef restoration, preservation of biodiversity, and the use of corals as model experimental organisms. In this study, we examine species-specific responses in growth and

www.academia.edu

Comparing the capacity of five different dietary treatments to optimise growth and nutritional composition in two scleractinian corals

Developing an optimal heterotrophic feeding regime has the potential to improve captive coral growth and health. This study evaluated the efficacy of three exogenous diets: Artemia nauplii (ART), a commercially available coral diet (Reef Roids) (RR), and a novel, micro-bound diet (ATF), against...

journals.plos.org

Elucidating an optimal diet for captive Acropora corals

Developing an optimal heterotrophic feeding regime has the potential to improve the growth and overall health of captive corals. This study evaluated …

www.sciencedirect.com

Influence of different feeding regimes on the survival, growth, and biochemical composition of Acropora coral recruits

Heterotrophic feeding in newly-settled coral planulae can potentially improve survivorship and accelerate early development in some species; however, an optimal diet to facilitate this does not currently exist. This study evaluated the efficacy of three heterotrophic feeding regimes (enriched...

journals.plos.org

"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


Nitrogen cycling in hte coral holobiont


BActeria and Sponges


Maintenance of Coral Reef Health (refferences at the end)


Optical Feedback Loop in Colorful Coral Bleaching


Richard Ross What's up with phosphate"

First off, thank you for your thoughtful comment.
I can really appreciate taking a step back and looking at things from a higher-level to consider the fact that I might be already on the right track.
As a mechanical engineer I do enjoy learning about the fine intricacies of how systems work. I will definitely be looking into the links and information you provided. Thanks for that.

Reflecting on what I had done months prior to observing the good coral growth and color I can say that I did increase feeding (the fish) and introduced aminos. Also varied the type of food more than usual.
I think once I resolve this GHA issue, I'll be trigger shy on introducing more food again. Especially considering the effects of overfeeding are not necessarily noticeable until it's too late (sort of). Any insight into this?

 

[MaxTremors]

That makes sense to me! In my case I do have a fuge running relatively well at the moment and my nitrates are always undetectable. Is there something else that I can do to help limit unwanted algaes?

I like your philosophy and wont implement PO4 exports at this time.


I completely agree I do need to up the CUC as I had a bit of a snail die-off. Now that I am thinking about it, it was around the same time the GHA was at its worst. Maybe a coincidence, probably not. I do have some nassarius snails left and a fighting conch.
What hermits do you recommend? The hermits I picked up at my LFS when my tank was newish loved to hunt and kill the snails.



Well it sounds like I'll be taking a trip to my LFS this weekend to start introducing new CUC.
On a side note, I am also dealing with aiptasia and after doing loads of research, I think I am going to pull the trigger on some Berghias if it gets any worse.

I would recommend either blue legs, scarlets, or Mexican red legs. The tiny little blue legs are probably the safest option, but so long as you provide extra shells and ensure that they have stuff to eat they shouldn’t kill too many snails. To a certain extent is just the reality of keeping both, there will inevitably be some casualties, I would recommend topping up once a year or so.

 

[LiftinTheVeil]

I would recommend either blue legs, scarlets, or Mexican red legs. The tiny little blue legs are probably the safest option, but so long as you provide extra shells and ensure that they have stuff to eat they shouldn’t kill too many snails. To a certain extent is just the reality of keeping both, there will inevitably be some casualties, I would recommend topping up once a year or so.

Thank you