Article: Demystifying SPS Coral Care

[Hans-Werner]

For me the most frequent cause for STN from the base is quite clear: Low phosphate concentrations and high alkalinities, 9 dKH and higher, at the same time.

I know this from own experience and from an old reefer who tried in the late 90s to keep alkalinity up at 9 dKH or a bit higher and to get phosphate down with Rowaphos. He had good growth on the tips, but always when combining both he got just as much STN from the base.

STN of the tips and exposed parts is in my eyes caused by a combination of high nitrate and low phosphate concentrations. Nitrate simply burns the tips when other nutrients are low.

In general SPS want higher phosphate concentrations than generally thought and believed. I recommend 0.1 ppm phosphate. There seem little or no problems with higher phosphate concentrations up to at least 0.5 ppm.

 

[Reeferbadness]

Nice write up. I would only add that when adding new sps to a tank, it's a good idea to put them lower in the tank (like on a frag rack) for a few weeks to let them acclimate to the lighting (assuming you are running higher par up high (200+). I didn't do this early on and lost a few sps. It also gives me a few weeks to figure out the best home for any new frags that i bring home.

 

[kdtorgy]

i see..

how about polyp extension guide or tips and tricks? My personal fear is i dont see any polyps and it is still colored fine (not fading or anything) then, all of the sudden, RTN overnight.. polyp extension gives me a hint that things are ok and i dont know if that's a valid metric or not

I’ve had a green slimmer for like 7 months. Great color but no PE. It’s more than doubled in size during the time. Can’t figure out why there is no PE. Other acros doing great so I don’t think it’s light, flow or water chemistry. Maybe fish picking at it?

 

[X-37B]

I’ve had a green slimmer for like 7 months. Great color but no PE. It’s more than doubled in size during the time. Can’t figure out why there is no PE. Other acros doing great so I don’t think it’s light, flow or water chemistry. Maybe fish picking at it?

Do you have a foxface. I caught mine chewing all the tips off my green slimer. Once I removed him the slimer took off. Funny as I had several other stags and it would only chew the tops of the green slimer, lol.

 

[Reef Psychology]

Demystifying SPS Coral Care
by Reefer Matt

Hello Reefers! I thought I’d share my thoughts and experience with SPS coral and how I care for them. In this article, I hope you’ll find something to take with you, and apply it to your tank.

Reefer Matt’s 75 Gallon SPS Tank

First, I’d like to start by addressing the notion that all SPS coral are difficult to keep. It’s not true. While they are generally suggested for experienced Reefers with a tank aged around a year, there are a few exceptions. Those brand new to reefing may have difficulty with any coral at first, but after they’ve gained knowledge and experience, it all becomes easier. The same is true with SPS coral.

Stability
SPS coral require stability. What that means is not constantly fooling around with light settings, or pressing all the buttons on wave makers, etc. Picking a setting and leaving the coral alone will go a long way in their health. The tricky part is that you have to guess which settings are adequate if you don’t have the tools to measure them. I always recommend using a par meter to help get lighting dialed in, but it’s not a requirement. More on that later.

Water Chemistry
Water chemistry is an important factor in keeping SPS coral. The Reefer should have an understanding of alkalinity and how to control it. SPS coral have a calcium carbonate skeleton that require sufficient levels of Alkalinity, Calcium, and Magnesium to grow. There is a broad range of suggested values for these, but I’d like to recommend what I think will give you the best success. Specific gravity should be between 1.024-1.026. Alkalinity will work well at 8-9 dkh. Calcium has a bigger window at 375-475 ppm. And though a little harder to test, I like to make sure the magnesium is around 1300-1400. Choosing a salt mix that has these values will help keep them stable, but alkalinity can be adjusted before use if necessary. For temperature, I aim for 77-80F. Success can be had outside these ranges, but I find this is the sweet spot for my tanks.

Nitrate and Phosphate
Nutrients like nitrates and phosphates can vary wildly. The commonly suggested “low” values, aren’t always true. If you are having success with LPS coral at a certain level, then trying SPS there is a good place to start. My SPS tanks have a nitrate range of 15-35 ppm, and phosphate around .03-.05 ppm. I prefer to keep nitrate around 10-15 ppm, but honestly haven’t noticed any ill effects. That may be because I keep a very strong CUC in my tanks, and algae is always at a minimum.

Ph
Ph will swing according to the environment that the tank is in. For example, a closed up room occupied with people and/or pets will lower Ph, because they emit CO2. This creates carbonic acid in the tank, and lowers Ph. I try to keep Ph around 8 - 8.4 as much as possible. Opening windows (in favorable weather), using a CO2 scrubber, and dosing alkalinity boosting elements (when required) can all help increase Ph. All in all, I don’t focus too much on chasing Ph, but I do pay attention to it.

Top View of Reefer Matt’s SPS Tank

Lighting
Lighting is important for all photosynthetic coral. Specifically, it’s important for the symbiotic zooxanthellae that live in the coral’s tissue. Those dinoflagellates (yes, that’s right!) provide the coral with energy to live. In turn the coral gives them a safe place to reside. More par isn’t always better. There are limits, and the coral will tell you by bleaching, or worse, polyp bailout. Finding the sweet spot to feed the zooxanthellae without “baking” or “shading” them is key to success.

In general, a range of 150-300 par with an adequate spectrum will grow healthy SPS coral. Higher par values are achievable and sometimes desired, but usually for peak coloration of the coral. I suggest staying in the lower range if trying SPS for the first time.

When lighting is too low, the coral usually turns a darker hue, often brown. This is the zooxanthellae trying to absorb more light. The opposite happens when lighting is too high. The coral will appear pale and faded. Acropora can shift colors and shades dramatically, and they probably will at first. This makes us think we did something wrong, but it’s just because our parameters don’t match where the coral came from. In time, they usually bounce back after being acclimated for many months (or longer!). But I wouldn’t declare defeat because of shifting colors as long as the polyps are extended. The key is to keep lighting stable, and only intervene if the coral start to become pale, as too high of light will kill faster than too low.

Flow
SPS coral require a lot of flow. I believe this is because they need more oxygen exchange than most coral due to a higher rate of photosynthesis from the zooxanthellae. Trying to quantify that flow is difficult, to say the least. There aren’t any portable hobby grade flow meters to measure flow, so at best it’s a guess. Luckily the coral can adapt within reason. At a minimum, you should always see water moving around in every corner of the tank. The polyps on the coral should be dancing around, but not constantly blown sideways like in a hurricane. Random, indirect flow is what to shoot for here.

Closeup of BigR Walt Disney Tenuis

If you are having issues with color on your SPS coral, flow can be adjusted instead of lighting in some cases. Lighting and flow go together like “peas and carrots”. If the coral are pale, try increasing the flow. If they are browning out, try decreasing it. I recommend adjusting one thing at a time for a couple weeks to see what corrects the issue. By tweaking lighting and flow, you can get those polyps out and color up the coral. But do it gradually over the course of weeks to months, not days.

STN/RTN
Slow tissue necrosis and rapid tissue necrosis are terms to describe when a SPS coral has had enough, and is sloughing off its tissue. The direct cause of this is unknown, but widely suggested to be from instability in parameters like alkalinity. Anyone who keeps SPS coral will likely run into this at some point. Some claim it is contagious to other coral. I have not experienced that myself.

What I do when I see tissue loss is keep an eye on it. If it keeps progressing, I will cut the coral just above the dead spot and remount it. It’s about a 50/50 chance, but better than doing nothing. Redipping the coral may also help, but really there is no “cure”. My best guess is that STN/RTN is a range of things that create the same symptom, but the cause is unique in each case. This may explain why some see it as contagious, while others do not.

STN on an Acropora frag

Misc. Advice and Ramblings
There are a few items that I haven’t addressed like substrate, rockscape, and dosing. For substrate and rock, I suggest going with what you like. As long as you follow basic reefing husbandry, those won’t affect your success much with SPS coral. Dosing (in a newer tank) won’t be required for a year or two in most cases. I suggest doing water changes as required to maintain alkalinity and calcium at first. When the tank starts to deplete those faster than a routine water change can handle, then consider dosing. That also goes for trace elements and the “magic potions” like aminos, etc. In an established tank that is already being dosed, you may have to make adjustments as the coral grow.

It is hard to keep different types of coral happy at the same time in a mixed reef tank. I was advised early on to setup a SPS only tank for SPS coral because it’s much easier. In a mixed reef, you have many different species that all like different parameters. Some want low light and low flow, for example. Some want high nutrients. Frankly, I’m always amazed to see the tanks of those who pull it off.

Side view of Reefer Matt’s SPS tank

Some beginner SPS coral to try include: Montipora, Pavona, Leptoseris, Pocillopora, Seriatopora, and Stylophora. You can see that I have most of those in my SPS reef tank. I suggest waiting until your tank is at least 8-12 months established before introducing SPS coral for best success.

In summary, my best advice to keeping SPS coral is to provide stability, have patience, pay attention, and do the required maintenance. Adjustments will probably be needed at first. Just keep them small and gradual until you find the sweet spot for your tank. Then don’t touch it! Lol! In time you will find out that SPS coral aren’t all as difficult as you’ve heard. Happy Reefing!

-Reefer Matt

In the military we were told exactly how and trained for a week to hit a moving target at 300 meters. Not everyone could do it. Many SPS are indeed hard to keep. Acropora in particular. I think it’s a misconception of “easy to understand methodology” vs “complex implementation”. Plus, a lot of what we do is dependent on intuition, which takes time (and losses) to gain. Worse, we are all one mistake away from a crash depending upon things we can/cannot control.

Otherwise, great write-up. Much appreciated!

 

[gizmodo]

This may sound like a no brainer now but it's become really obvious to me just how important stability, simplicity and lighting really are. I had to learn to stop tweaking with my tank and just let it be. Now I run AWCs and try to mess with the tank as little as possible. Lighting coverage was also way more important that we used to believe 10 years ago and after 15 years of running point lighting I'm switching to flat panel lighting.

 

[Rocky Mountain Reef]

I am starting with acropora for the last 6 months...getting really addicted to them. Is there anyone out there that might be interested in helping me fine tune my lighting? I get reasonable coloration, but want it to really pop like Reefer Matt....
I have a 210 peninsula tank with two 48" AI Blades (Grow lamps), two XR15's, a Kessil AP9X and a Kessil A500X. The tank is 60"x30"x30"

 

[kdtorgy]

Do you have a foxface. I caught mine chewing all the tips off my green slimer. Once I removed him the slimer took off. Funny as I had several other stags and it would only chew the tops of the green slimer, lol.

No, but I do have an aptasia eating file fish. Caught him picking at my acanthophyllia so he was re-homed yesterday. Will see if this makes a difference. I do have a yellow, hippo and kole tang. I'll keep an eye on them. I also have a flame angel.

 

[Charlie the Reefer]

Thank you for this nice article. Awesome pics by the way.

May I ask what your CUC is comprised of approximately? I struggle with maintaining decent detectable nutrient levels while also staving off nuisance algae growth.

 

[Reefer Matt]

Thank you for this nice article. Awesome pics by the way.

May I ask what your CUC is comprised of approximately? I struggle with maintaining decent detectable nutrient levels while also staving off nuisance algae growth.

I have 3-4 pincushion urchins, a large brittle star (mostly cause it’s cool to see), about 50-60 astrea snails, and a handful of hermits.

 

[helijamal]

No, but I do have an aptasia eating file fish. Caught him picking at my acanthophyllia so he was re-homed yesterday. Will see if this makes a difference. I do have a yellow, hippo and kole tang. I'll keep an eye on them. I also have a flame angel.

I had a flame angel that loved polyps. It was like caviar to him.

 

[Townes_Van_Camp]

Demystifying SPS Coral Care
by Reefer Matt

Hello Reefers! I thought I’d share my thoughts and experience with SPS coral and how I care for them. In this article, I hope you’ll find something to take with you, and apply it to your tank.

Reefer Matt’s 75 Gallon SPS Tank

First, I’d like to start by addressing the notion that all SPS coral are difficult to keep. It’s not true. While they are generally suggested for experienced Reefers with a tank aged around a year, there are a few exceptions. Those brand new to reefing may have difficulty with any coral at first, but after they’ve gained knowledge and experience, it all becomes easier. The same is true with SPS coral.

Stability
SPS coral require stability. What that means is not constantly fooling around with light settings, or pressing all the buttons on wave makers, etc. Picking a setting and leaving the coral alone will go a long way in their health. The tricky part is that you have to guess which settings are adequate if you don’t have the tools to measure them. I always recommend using a par meter to help get lighting dialed in, but it’s not a requirement. More on that later.

Water Chemistry
Water chemistry is an important factor in keeping SPS coral. The Reefer should have an understanding of alkalinity and how to control it. SPS coral have a calcium carbonate skeleton that require sufficient levels of Alkalinity, Calcium, and Magnesium to grow. There is a broad range of suggested values for these, but I’d like to recommend what I think will give you the best success. Specific gravity should be between 1.024-1.026. Alkalinity will work well at 8-9 dkh. Calcium has a bigger window at 375-475 ppm. And though a little harder to test, I like to make sure the magnesium is around 1300-1400. Choosing a salt mix that has these values will help keep them stable, but alkalinity can be adjusted before use if necessary. For temperature, I aim for 77-80F. Success can be had outside these ranges, but I find this is the sweet spot for my tanks.

Nitrate and Phosphate
Nutrients like nitrates and phosphates can vary wildly. The commonly suggested “low” values, aren’t always true. If you are having success with LPS coral at a certain level, then trying SPS there is a good place to start. My SPS tanks have a nitrate range of 15-35 ppm, and phosphate around .03-.05 ppm. I prefer to keep nitrate around 10-15 ppm, but honestly haven’t noticed any ill effects. That may be because I keep a very strong CUC in my tanks, and algae is always at a minimum.

Ph
Ph will swing according to the environment that the tank is in. For example, a closed up room occupied with people and/or pets will lower Ph, because they emit CO2. This creates carbonic acid in the tank, and lowers Ph. I try to keep Ph around 8 - 8.4 as much as possible. Opening windows (in favorable weather), using a CO2 scrubber, and dosing alkalinity boosting elements (when required) can all help increase Ph. All in all, I don’t focus too much on chasing Ph, but I do pay attention to it.

Top View of Reefer Matt’s SPS Tank

Lighting
Lighting is important for all photosynthetic coral. Specifically, it’s important for the symbiotic zooxanthellae that live in the coral’s tissue. Those dinoflagellates (yes, that’s right!) provide the coral with energy to live. In turn the coral gives them a safe place to reside. More par isn’t always better. There are limits, and the coral will tell you by bleaching, or worse, polyp bailout. Finding the sweet spot to feed the zooxanthellae without “baking” or “shading” them is key to success.

In general, a range of 150-300 par with an adequate spectrum will grow healthy SPS coral. Higher par values are achievable and sometimes desired, but usually for peak coloration of the coral. I suggest staying in the lower range if trying SPS for the first time.

When lighting is too low, the coral usually turns a darker hue, often brown. This is the zooxanthellae trying to absorb more light. The opposite happens when lighting is too high. The coral will appear pale and faded. Acropora can shift colors and shades dramatically, and they probably will at first. This makes us think we did something wrong, but it’s just because our parameters don’t match where the coral came from. In time, they usually bounce back after being acclimated for many months (or longer!). But I wouldn’t declare defeat because of shifting colors as long as the polyps are extended. The key is to keep lighting stable, and only intervene if the coral start to become pale, as too high of light will kill faster than too low.

Flow
SPS coral require a lot of flow. I believe this is because they need more oxygen exchange than most coral due to a higher rate of photosynthesis from the zooxanthellae. Trying to quantify that flow is difficult, to say the least. There aren’t any portable hobby grade flow meters to measure flow, so at best it’s a guess. Luckily the coral can adapt within reason. At a minimum, you should always see water moving around in every corner of the tank. The polyps on the coral should be dancing around, but not constantly blown sideways like in a hurricane. Random, indirect flow is what to shoot for here.

Closeup of BigR Walt Disney Tenuis

If you are having issues with color on your SPS coral, flow can be adjusted instead of lighting in some cases. Lighting and flow go together like “peas and carrots”. If the coral are pale, try increasing the flow. If they are browning out, try decreasing it. I recommend adjusting one thing at a time for a couple weeks to see what corrects the issue. By tweaking lighting and flow, you can get those polyps out and color up the coral. But do it gradually over the course of weeks to months, not days.

STN/RTN
Slow tissue necrosis and rapid tissue necrosis are terms to describe when a SPS coral has had enough, and is sloughing off its tissue. The direct cause of this is unknown, but widely suggested to be from instability in parameters like alkalinity. Anyone who keeps SPS coral will likely run into this at some point. Some claim it is contagious to other coral. I have not experienced that myself.

What I do when I see tissue loss is keep an eye on it. If it keeps progressing, I will cut the coral just above the dead spot and remount it. It’s about a 50/50 chance, but better than doing nothing. Redipping the coral may also help, but really there is no “cure”. My best guess is that STN/RTN is a range of things that create the same symptom, but the cause is unique in each case. This may explain why some see it as contagious, while others do not.

STN on an Acropora frag

Misc. Advice and Ramblings
There are a few items that I haven’t addressed like substrate, rockscape, and dosing. For substrate and rock, I suggest going with what you like. As long as you follow basic reefing husbandry, those won’t affect your success much with SPS coral. Dosing (in a newer tank) won’t be required for a year or two in most cases. I suggest doing water changes as required to maintain alkalinity and calcium at first. When the tank starts to deplete those faster than a routine water change can handle, then consider dosing. That also goes for trace elements and the “magic potions” like aminos, etc. In an established tank that is already being dosed, you may have to make adjustments as the coral grow.

It is hard to keep different types of coral happy at the same time in a mixed reef tank. I was advised early on to setup a SPS only tank for SPS coral because it’s much easier. In a mixed reef, you have many different species that all like different parameters. Some want low light and low flow, for example. Some want high nutrients. Frankly, I’m always amazed to see the tanks of those who pull it off.

Side view of Reefer Matt’s SPS tank

Some beginner SPS coral to try include: Montipora, Pavona, Leptoseris, Pocillopora, Seriatopora, and Stylophora. You can see that I have most of those in my SPS reef tank. I suggest waiting until your tank is at least 8-12 months established before introducing SPS coral for best success.

In summary, my best advice to keeping SPS coral is to provide stability, have patience, pay attention, and do the required maintenance. Adjustments will probably be needed at first. Just keep them small and gradual until you find the sweet spot for your tank. Then don’t touch it! Lol! In time you will find out that SPS coral aren’t all as difficult as you’ve heard. Happy Reefing!

-Reefer Matt

In, and thank you for the great article!

 

[Borat]

Good article - you may have included "patience" section. Put one SPS stick in your reef tank - wait for 1-2 months to see if it is OK... Then maybe put a couple of more SPS sticks.

Another one is that SPS corals can be ranked in terms of ease of care - one should always start with the easiest (e.g. plating montipora), learn how to look after them. Then add next easiest - maybe birdsnest etc.. Then maybe after your montiporas of varying difficulty seem to settle in - try adding easy acropora (maybe bali slimer) etc..