How to feed your corallivore

lulubap · Jan 16, 2023

So, I recently asked on here if some kind sea star experts could ID my sea star that I’ve had in captivity for 6 months.

I found out, with the help of @ISpeakForTheSeas and @AydenLincoln that this star most closely resembles Culcita sp. or Culcita Novaguineae, which is actually a corallivore.

Since this species eats SPS and favors pocillopora, it made sense why he never went after my soft coral. However, all this time, he’d been living off of supposedly biofilm and seaweed. So, he was nearing the time slot where sea stars die from malnutrition.

So, I set out to buy some SPS.

Avoiding shipping costs at the expense of uncertain coral IDs, I got some pocillopora damicornis (hopefully) locally and the people I got them from generously threw in a large montipora cap and some acropora / digitata frags.

My main issue is my light and my nutrients. I’ve always run a very high nutrient system. Last time I tested them, my nitrates were 50 before I did a water change. My light is a Kessil a80 which I thought would be more than enough for some soft coral.

However, now I have SPS and i’ll have to fix my parameters and make do. This thread exists so I can update and document how I feed Culcita Novaguineae , as well as see if some SPS oriented growers can give me some tips on how to grow out my new coral for my sea star’s benefit.

Any info or input is much appreciated.

Pocillopora damicornis (I hope)

Unknown acro or digi frag (i’m terrible at SPS IDS)

some more SPS frags which have not opened yet (I don’t blame them)

Super big red monti cap!

If the couple who generously sold me these frags is reading this, thank you again!

DanyL · Jan 16, 2023

I got to admit, growing SPS specifically to feed a star fish is a first to me

The corals you received as freebies are all Montiporas, cup and digitata.
These are generally considered as hardy, easy to grow corals, they are less delicate than acros, and many had great success transitioning from growing softies and some LPS corals to these.

As for how to take care of them, mainly I would say is to make sure to maintain your Alk, Cal and Mag levels, as these would be consumed by any LPS and SPS coral at greater amounts that with softies. Instability of the three may lead to what is called STN/RTN (Slow/Rapid Tissue Narcosis), where the coral looses its tissue and essentially dies.
You would also want to make sure your water is clean, low nutrients are not a hard stone requirement to maintain, I wouldn't chase numbers but I would not want them to be crazy high as well as to fluctuate neither.
I would put more attention to your RODI water, making sure TDS stays at 0 and maintain it regularly as it climbs up.

Another point you'd want to make sure is providing enough light, SPS demand more light than others, so putting them at the top of your aquascape is a good idea to start with, however depending on the PAR your lights put out this may not be enough and you'll need to supplement with additional light source.

These are the basics of keeping simple SPS corals, there are a lot more things that you may need to learn as you go and encounter them, but it's should give you a solid ground to start from in my opinion.

Good Luck!

lulubap · Jan 16, 2023

DanyL said:
I got to admit, growing SPS specifically to feed a star fish is a first to me

The corals you received as freebies are all Montiporas, cup and digitata.
These are generally considered as hardy, easy to grow corals, they are less delicate than acros, and many had great success transitioning from growing softies and some LPS corals to these.

As for how to take care of them, mainly I would say is to make sure to maintain your Alk, Cal and Mag levels, as these would be consumed by any LPS and SPS coral at greater amounts that with softies. Instability of the three may lead to what is called STN/RTN (Slow/Rapid Tissue Narcosis), where the coral looses its tissue and essentially dies.
You would also want to make sure your water is clean, low nutrients are not a hard stone requirement to maintain, I wouldn't chase numbers but I would not want them to be crazy high as well as to fluctuate neither.
I would put more attention to your RODI water, making sure TDS stays at 0 and maintain it regularly as it climbs up.

Another point you'd want to make sure is providing enough light, SPS demand more light than others, so putting them at the top of your aquascape is a good idea to start with, however depending on the PAR your lights put out this may not be enough and you'll need to supplement with additional light source.

These are the basics of keeping simple SPS corals, there are a lot more things that you may need to learn as you go and encounter them, but it's should give you a solid ground to start from in my opinion.

Good Luck!

I like sea stars more than the idea of growing SPS, so although odd I do find the beginning of this journey exciting.

Definitely will be monitoring my Ca, KH, and Mg from now on. I have a full test kit at home. I’m also going to be working on lowering my nitrates at least to the 20ppm mark. Do you have any tips for that? I’m thinking of adding some macroalgae to the display to get started.

I do have an AI Prime 16HD i was going to use for a classroom tank, but I think I need it more right now. This should be enough PAR to make up for the a80.

I get RODI from my LFS (which I work for, so it’s free) so I want to say i’m fairly certain it’s 0 TDS

Thank you for your help. I’ll be keeping updates when possible

DanyL · Jan 16, 2023

Sounds like like you're all setup!

Macro algae is a great way to export nutrients, I would start with that.
Another option is to introduce a carbon source to grow bacteria that will consume the nitrates (and a bit of phosphate) and export it as an organic matter using a skimmer or water changes.

Good luck

lulubap · Jan 21, 2023

1/21/23: woke up today and found a fallen and violated pocillopora frag

I’m not sure what the cause was, but I found my sea star near it…

lulubap · Jan 21, 2023

Just came home from work and caught him in the act. It seems I’ll have to start growing more..

DanyL · Jan 22, 2023

At this rate, I think you'll end up needing a separate SPS grow out tank to keep up

lulubap · Jan 22, 2023

DanyL said:
At this rate, I think you'll end up needing a separate SPS grow out tank to keep up

It does seem that way He ate it without remorse and very quickly. I think I can get away with setting up a cheap tank on the side ; )

Here he is satisfied next to the aftermath

DanyL · Jan 22, 2023

Haha he does look happy and satisfied

You can possibly extend your current system by plumbing a second tank instead of setting up a separate one.
This would allow you to get a slightly better stability as well as speed up the cycling process (possibly even skipping it).

Miami Reef · Jan 22, 2023

I would keep elevated alkalinity (around 10-12dKH) for faster growth of stony corals. Higher nutrients (around 0.10ppm phosphates) can also help with quicker tissue growth.

Good luck! This is the first time I’ve seen someone try to grow SPS for a starfish!

Seymo44 · Jan 22, 2023

This is very interesting. If you do set up a tank on the side to feed him, grow pocilipora, birdsnest, and stylophora. These “sps” are super fast growing, and in my opinion more hardy than pretty much anything else in my tanks. Branches of these corals can be easily cut off and fed to the star.

lulubap · Jan 22, 2023

Miami Reef said:
I would keep elevated alkalinity (around 10-12dKH) for faster growth of stony corals. Higher nutrients (around 0.10ppm phosphates) can also help with quicker tissue growth.

Good luck! This is the first time I’ve seen someone try to grow SPS for a starfish!

im looking to do a full spectrum water test at my local LFS, since i don’t have the means to measure phosphates. Is it possible to recover the half eaten frag for tissue regeneration?

I actually almost loathe the idea of keeping SPS; i find it unnecessarily frustrating in comparison to soft coral. But that might just be the fact that I enjoy keeping other marine animals instead. Anyhow, I’ll have to start finding it gratifying soon, because this may end up being my life for as long as the sea star lives : )

lulubap · Jan 22, 2023

Seymo44 said:
This is very interesting. If you do set up a tank on the side to feed him, grow pocilipora, birdsnest, and stylophora. These “sps” are super fast growing, and in my opinion more hardy than pretty much anything else in my tanks. Branches of these corals can be easily cut off and fed to the star.

I see! I’m definitely going to be keeping pocillopora from now on, but I’ll have to experiment a bit with birds nest and stylo since they’re not exclusive parts of the sea star’s diet. I know for sure this is culcita sp. because he seems to favor my pocillopora over all, but I’ll have to do some experimenting with certain sps to see his preferences. Thank you for the advice, though! I’m completely new when it comes to this.

lulubap · Jan 22, 2023

1/22/23: He seems to have ignored a fallen digi frag. I’ll try feeding it to him, but I hope I don’t have to cross montipora digitata off the list

Miami Reef · Jan 22, 2023

lulubap said:
im looking to do a full spectrum water test at my local LFS, since i don’t have the means to measure phosphates. Is it possible to recover the half eaten frag for tissue regeneration?

I actually almost loathe the idea of keeping SPS; i find it unnecessarily frustrating in comparison to soft coral. But that might just be the fact that I enjoy keeping other marine animals instead. Anyhow, I’ll have to start finding it gratifying soon, because this may end up being my life for as long as the sea star lives : )

Keeping SPS is easy, especially if you don’t care about their coloration.

Don’t even worry about nutrients. As long as the are elevated you are fine. High alkalinity is good for fast growth.

Those SPS are super easy. I wouldn’t worry.

A par of 250-350 is good. Pick any spectrum you like with your LEDs.

It’s really hard to mess up with my advice.

lulubap · Jan 22, 2023

Miami Reef said:
Keeping SPS is easy, especially if you don’t care about their coloration.

Don’t even worry about nutrients. As long as the are elevated you are fine. High alkalinity is good for fast growth.

Those SPS are super easy. I wouldn’t worry.

A par of 250-350 is good. Pick any spectrum you like with your LEDs.

It’s really hard to mess up with my advice.

I have an ai prime 16hd on my tank right now, so I think I won’t have to worry about par. I’ll still use this as an excuse to grow some macro to make sure they’re not too bothered by my grossly high nutrients though (i also just love macroalgae).

Do you think the pocillopora frag can be recovered? Or should I just leave it to him. I have a smaller frag hiding on the rock in a game of deadly hide and seek..

Rmckoy · Jan 22, 2023

Miami Reef said:
I would keep elevated alkalinity (around 10-12dKH) for faster growth of stony corals. Higher nutrients (around 0.10ppm phosphates) can also help with quicker tissue growth.

Good luck! This is the first time I’ve seen someone try to grow SPS for a starfish!

Sounds similar to us eating prime
Rib or some expensive fancy restaurant every day .
I would be worried if the long term
Cost of supplying enough sps to feed the starfish

lulubap · Jan 22, 2023

Rmckoy said:
Sounds similar to us eating prime
Rib or some expensive fancy restaurant every day .
I would be worried if the long term
Cost of supplying enough sps to feed the starfish

I’m looking at exclusively keeping pocillopora damicornis, which is a relatively fast growing coral. I already have a tank on the side I can grow it out in.

The hobby is already somewhat expensive and tedious, in my opinion. If people do something like finding pleasure in growing out expensive SPS for themselves, or keeping routine schedules to feed their seahorses or other expert animals, I find pleasure in doing whatever I can to feed my sea star.

ISpeakForTheSeas · Jan 22, 2023

lulubap said:
Do you think the pocillopora frag can be recovered? Or should I just leave it to him. I have a smaller frag hiding on the rock in a game of deadly hide and seek..

I’d say give it a try and see if the frag comes back at all. Worst case, it doesn’t come back and you toss it out later, best case it does come back and you have more food to offer later.