420 Gallon shark/ preditor aquarium

[14crazychris]

Hi Everyone,

So I've been keeping fish over a decade now and really wanting to try something new. I've kept two mixed marine systems in the past and navigated back to freshwater as my day job is reef aquarium installation/maintenance. Currently I have an Asian arowana and two freshwater stingrays which are in a 5x3x2 foot aquarium. The plan was to upgrade their tank at the end of this year/early next year to a 8x3x2.5 foot aquarium holding around 1600 litres plus a sump, so around 1800 litres total (around 420 gallon display )

I am obsessed with the rays and after a trip to the aquarium two months ago I am really thinking about switching my upgrade from a freshwater monster fish tank to a marine predator/shark tank.

So the tank in question would be 8 feet long, 3 feet wide and 2.5ft tall with a large sump with sponges, rowa phos/carbon, 15kg of biomedia a chaeto and caulerpa refugium and a large area for mangroves. The tank will just be sand with some rock, probably around 50-70kg. I am also planning to run the display as a planted tank so ideally all the rocks would be covered in various macro algaes. I'm sure all CUC would be eaten? Like snails or hermits etc. My planned stocking would ideally be 6-8 fish.

3x sharks (Bamboo/cat/epaulette/horned etc)
1x stingray (cortex/ yellow Think blue spots seem to be very sensitive?)

2-3x groupers

However I wanted to come on here to run a few ideas through you guys to help me make the right informed descision. I love to do plenty of research and never impulse buy, hence my 3-6month plan ahead of time.

Can anyone recommend stocking ideas, which fish work best?

Maybe some suggestions I've missed? Any big no no's or sharks to avoid?

Any tips or videos/threads to read through? I think I've read through most of them now haha

Also lighting ideas? As I won't be keeping corals what's the best Kelvin rating and colour spectrum to see the fish colours best? And to also grow all the algae, Maybe a cool white?

Temp wise, I see many sharks doing well at cooler temps, around 22-24 degrees Celsius?

Any help or advice appreciated, or If you think this is a silly idea please feel free to put me off!

Many thanks,
Chris

 

[Aspect]

You're going to need a super large protein skimmer. I recommend a Bubble Magus B12. A tank with shorter height and more width would be better for sharks if that is possible for you. Stocking wise you can do most any fish that is 6" or larger, that size should be safe from being shark food. No triggers, angels, or wrasse as they will possibly nip at the sharks. You will need fiji pink sand or lighter as anything coarser will scratch the sharks and lead to infection. CuC will be impossible. Dim lights will be best for predator tanks. I run my tank at 75F, keeping it cooler will be better as sharks are oxygen hogs.

 

[14crazychris]

You're going to need a super large protein skimmer. I recommend a Bubble Magus B12. A shorter height with more width would be better for sharks if that is possible for you. Stocking wise you can do most any fish that is 6" or larger, that size should be safe from being shark food. No triggers, angels, or wrasse as they will possibly nip at the sharks. You will need fiji pink sand or lighter as anything coarser will scratch the sharks and lead to infection. CuC will be impossible. Dim lights will be best for predator tanks. I run my tank at 75F, keeping it cooler will be better as sharks are oxygen hogs.

Okay thank you for your reply, yes fine sand is definitly on the list, I prefer the look as well. Is there no CuC whatsoever? I assumed any crabs and urchins would be eaten but even turbo or trocus snails? The sharks are the main species I want to keep so any fish I add will need to work around them, even if the Ray is a no go 3 sharks and 3 groupers would be nice. Good to know about temps, atleast that will save some energy costs in the winter. I was planning to run three standard spotlights on the tank, probably a cool white, only on in the evenings for around 5/6 hours. Hopefully this will keep algae levels down as well. Are there any starfish that are good CuC, I've only ever looked at starfish for a reef tank or are the FOWLR starfish just decorative as well, rather than serving a purpose?

I will take a look into skimmers as well, what about flow? Is high flow necessary or will I get away with a large return pump and wave maker?
Thank you

 

[Aspect]

Okay thank you for your reply, yes fine sand is definitly on the list, I prefer the look as well. Is there no CuC whatsoever? I assumed any crabs and urchins would be eaten but even turbo or trocus snails? The sharks are the main species I want to keep so any fish I add will need to work around them, even if the Ray is a no go 3 sharks and 3 groupers would be nice. Good to know about temps, atleast that will save some energy costs in the winter. I was planning to run three standard spotlights on the tank, probably a cool white, only on in the evenings for around 5/6 hours. Hopefully this will keep algae levels down as well. Are there any starfish that are good CuC, I've only ever looked at starfish for a reef tank or are the FOWLR starfish just decorative as well, rather than serving a purpose?

I will take a look into skimmers as well, what about flow? Is high flow necessary or will I get away with a large return pump and wave maker?
Thank you

Flow doesn't really matter in a shark tank as they will spend basically all of their time on the sand bed. Snails will not last more than a day. These sharks suck their food up and will easily suck a snail right out of their shell. I had 0 success with any clean up crew. Would not recommend an urchin as they could irritate the shark, same with crabs. Your clean up crew will have to consist of tangs/foxfaces/large gobies. I have had success with sleeper banded gobies although they are smaller they hide very well. You will want a lot of hiding spaces for these sharks. They can get stressed out very very easily. Never use copper in the tank as it is highly toxic to them.

 

[14crazychris]

Flow doesn't really matter in a shark tank as they will spend basically all of their time on the sand bed. Snails will not last more than a day. These sharks suck their food up and will easily suck a snail right out of their shell. I had 0 success with any clean up crew. Would not recommend an urchin as they could irritate the shark, same with crabs. Your clean up crew will have to consist of tangs/foxfaces/large gobies. I have had success with sleeper banded gobies although they are smaller they hide very well. You will want a lot of hiding spaces for these sharks. They can get stressed out very very easily. Never use copper in the tank as it is highly toxic to them.

Awesome thats good to know! Yeah I plan to create a big rock area on one side of the tank and then big open sand bed on the other. I know I will need to make the rocks extra secure so maybe I'll need a few tubs if reef cement. How's do the sharks cope with nutrient levels? I'm hoping I can grow a huge forest of macro algae in the tank but are they sensitive to high levels of phosphate and nitrate?

Thanks

 

[Aspect]

Awesome thats good to know! Yeah I plan to create a big rock area on one side of the tank and then big open sand bed on the other. I know I will need to make the rocks extra secure so maybe I'll need a few tubs if reef cement. How's do the sharks cope with nutrient levels? I'm hoping I can grow a huge forest of macro algae in the tank but are they sensitive to high levels of phosphate and nitrate?

Thanks

Phosphate no although not much research on it. High nitrate levels will stress them out. <40 ime does not cause ill effects.

 

[WheatToast]

Not a predator owner, but here's what I've got:

Elasmobranchs (sharks and rays) will probably ignore macroalgae, but be careful to secure them properly. Calcified, rooted macroalgae, like Udotea, and seagrasses are probably unsuitable as they would get knocked over. While macroalgae can be used for filtration without (and sometimes suffering from) skimmers and chemical filtration, I am pretty sure they alone cannot be used with elasmobranchs, due to their high waste output.
Caulerpa and Gracilaria (ogo) are good diplay algae that grow fast and shouldn't be too hard to obtain where you are (remember to harvest the Caulerpa regularly to avoid it going sexual). Ulva (sea lettuce) is another good refugium algae that enjoys high nutrients. Codium (dead man's fingers) doesn't grow very fast, but is very undemanding.
Macroalgae lighting information:
https://www.marineplantbook.com/marinebookpage8.htm (older site, doesn't cover LED's very much)
https://www.plantedreef.co.uk/best-lighting-for-macroalgae
Awesome images of planted elasmobranch tanks:
http://www.benthicsharks.ca/

Rays probably won't be an issue with sharks. Aquarium Sharks & Rays by Scott W. Michael (pretty outdated, but still useful in many aspects) also recommends avoiding:
- Scorpionfish and lionfish (Scorpaenidae)
- Butterflyfish (Chaetodontidae)
- Filefish (Monacanthidae)
- Pufferfish and porcupinefish (Tetraodontidae and Diodontidae)
Many can envenom or peck at elasmobranchs.
The books also warns that groupers may feed too aggressively for elasmobranchs to catch any food, though tongs can be used to avoid this issue.
Large conchs (ex. Macrostrombus costatus and Aliger gigas) might work well with small elasmobranchs, though these are rare. Aquarium Sharks & Rays also recommends large cowries (Cypraeidae) and pencil urchins (Cidaridae). True starfish often starve in aquaria (and are usually not recommended as clean up crew), and brittle stars are on the more fragile side, though are easy to care for and are recommended by Aquarium Sharks & Rays.

Most of the elasmobranchs you mentioned are tropical species, though horn sharks (Heterodontus francisci) and round stingrays (Urobatis halleri) (this is the species that is usually called the "Cortez ray" and incorrectly identified as Urobatis maculatus) are temperate species and Aquarium Sharks & Rays states their upper temperature limits are 21° and 22° celsius respectively. While they are very common in tropical tanks and can do very well, I am not sure how comfortable they would feel. There are two species of blue spotted stingray, Taeniura lymma and Neotrygon kuhlii, that are common in the trade. Neotrygon kuhlii is more triangular in appearance and is easier to care for, but it grows up to about 47 cm wide. Taeniura lymma is more rounded in appearance and is notorious for being difficult to care for, though it only grows 35 cm wide.

Bluespotted ribbontail ray (Taeniura lymma):


Kuhl's maskray (Neotrygon kuhlii):


@Jay Hemdal
@killemall

Good luck with your new system! Please do keep us updated!

 

[Aspect]

Yeah, that's true if you're contemplating getting a horn shark you will need to keep the aquarium at 70F or cooler. As far as groupers feeding, a healthy shark will definitely get their fair share. I would get tongs that are long either way as it makes feeding easier with new sharks.

 

[Jay Hemdal]

Skip the bamboos, they grow too large (3'+) Horn sharks prefer cooler water. Concentrate on the coral catsharks and the epaulettes. Try to get females as the males get pretty aggressive when mating.

I think bluespot rays are too delicate. The blue diamond ray, D. kuhli is sturdier. Cortez rays are great, but most that are sold are actually just California round rays.

Watch the type of grouper you get - there are captive raised bumblebee groupers that are really pretty (yellow and black) but they reach 8' long.

Jay

 

[14crazychris]

Not a predator owner, but here's what I've got:

Elasmobranchs (sharks and rays) will probably ignore macroalgae, but be careful to secure them properly. Calcified, rooted macroalgae, like Udotea, and seagrasses are probably unsuitable as they would get knocked over. While macroalgae can be used for filtration without (and sometimes suffering from) skimmers and chemical filtration, I am pretty sure they alone cannot be used with elasmobranchs, due to their high waste output.
Caulerpa and Gracilaria (ogo) are good diplay algae that grow fast and shouldn't be too hard to obtain where you are (remember to harvest the Caulerpa regularly to avoid it going sexual). Ulva (sea lettuce) is another good refugium algae that enjoys high nutrients. Codium (dead man's fingers) doesn't grow very fast, but is very undemanding.
Macroalgae lighting information:
https://www.marineplantbook.com/marinebookpage8.htm (older site, doesn't cover LED's very much)
https://www.plantedreef.co.uk/best-lighting-for-macroalgae
Awesome images of planted elasmobranch tanks:
http://www.benthicsharks.ca/

Rays probably won't be an issue with sharks. Aquarium Sharks & Rays by Scott W. Michael (pretty outdated, but still useful in many aspects) also recommends avoiding:
- Scorpionfish and lionfish (Scorpaenidae)
- Butterflyfish (Chaetodontidae)
- Filefish (Monacanthidae)
- Pufferfish and porcupinefish (Tetraodontidae and Diodontidae)
Many can envenom or peck at elasmobranchs.
The books also warns that groupers may feed too aggressively for elasmobranchs to catch any food, though tongs can be used to avoid this issue.
Large conchs (ex. Macrostrombus costatus and Aliger gigas) might work well with small elasmobranchs, though these are rare. Aquarium Sharks & Rays also recommends large cowries (Cypraeidae) and pencil urchins (Cidaridae). True starfish often starve in aquaria (and are usually not recommended as clean up crew), and brittle stars are on the more fragile side, though are easy to care for and are recommended by Aquarium Sharks & Rays.

Most of the elasmobranchs you mentioned are tropical species, though horn sharks (Heterodontus francisci) and round stingrays (Urobatis halleri) (this is the species that is usually called the "Cortez ray" and incorrectly identified as Urobatis maculatus) are temperate species and Aquarium Sharks & Rays states their upper temperature limits are 21° and 22° celsius respectively. While they are very common in tropical tanks and can do very well, I am not sure how comfortable they would feel. There are two species of blue spotted stingray, Taeniura lymma and Neotrygon kuhlii, that are common in the trade. Neotrygon kuhlii is more triangular in appearance and is easier to care for, but it grows up to about 47 cm wide. Taeniura lymma is more rounded in appearance and is notorious for being difficult to care for, though it only grows 35 cm wide.

Bluespotted ribbontail ray (Taeniura lymma):


Kuhl's maskray (Neotrygon kuhlii):


@Jay Hemdal
@killemall

Good luck with your new system! Please do keep us updated!

Thank you so much for all of that information you provided, I can see you went to some effort to put that reply together and those links are great! Just what I needed to have a look at!

Id rather not keep any super sensitive species so might have to give the rays and the horn shark a miss (even though the horn was my favourite lol) , especially as my current tropical tank reaches 27/28 degrees in peak summer here. The blue spot is lovely but sounds like it could be quite demanding, I think sticking to one epaulettes and a couple cat sharks would be more suitable.

For the clean up crew a couple large brittle stars maybe useful! And I will look at the large coweries, think I’ve only seen small ones sold here unless they are a different species. My list for macro algae’s so far is Caulerpa, Ulva and Blue Ochtodes. I have a friend who has a nice red macro algae growing well in their sump but I havnt identified the species yet.

As for groupers I was looking at the coral grouper and a blue line. I really like the panther grouper but looks like it will get quite large and add considerably to the bioload. Any other groupers suggested to look over?

once again thank you for the help, I will have a read over all of those benthic shark species. The smaller species would be best!

thanks

 

[14crazychris]

Yeah, that's true if you're contemplating getting a horn shark you will need to keep the aquarium at 70F or cooler. As far as groupers feeding, a healthy shark will definitely get their fair share. I would get tongs that are long either way as it makes feeding easier with new sharks.

Yeah I have some 2 foot long stainless steel tongs which I can use. I used to use them for my freshwater rays but they have now learnt to be more agressive at feeding time. I will have to do some more research into the horn shark and weather it can cope with elevated temperatures in the summer months, otherwise I will likely give it a miss.

thanks

 

[Aspect]

I think a pod culture should thrive in a predator tank like this ironically since they wouldn't have any predators. A large enough colony should be able to clean your tank up quite well.

 

[14crazychris]

Skip the bamboos, they grow too large (3'+) Horn sharks prefer cooler water. Concentrate on the coral catsharks and the epaulettes. Try to get females as the males get pretty aggressive when mating.

I think bluespot rays are too delicate. The blue diamond ray, D. kuhli is sturdier. Cortez rays are great, but most that are sold are actually just California round rays.

Watch the type of grouper you get - there are captive raised bumblebee groupers that are really pretty (yellow and black) but they reach 8' long.

Jay

Great to know! The bamboo is crossed off the list! Judging by the responses so far the epaulettes and coral cats seem to be the winners I think I will end up with. Do the females tend to get larger? Would all males or all females be best? Also is it advisable to purchase them in egg form or fully developed? Is this purely down to owners choice or are there any positive and negatives to this?

yes Bumblee bees are definitely a big no! More looking at the coral grouper and blue line unless anyone has suggestions of some others to look at?

thank you

 

[14crazychris]

I think a pod culture should thrive in a predator tank like this ironically since they wouldn't have any predators. A large enough colony should be able to clean your tank up quite well.

That’s true! Maybe a few large brittle stars will help with any larger particles of waste as well. Im planning to start with dry rock to avoid hitchhikers so maybe I should purchase some live zooplankton or pod cultures once the tank is settled?

Im waiting to hear back from a couple tank manufactueres about the tank cost/installation

 

[Aspect]

That’s true! Maybe a few large brittle stars will help with any larger particles of waste as well. Im planning to start with dry rock to avoid hitchhikers so maybe I should purchase some live zooplankton or pod cultures once the tank is settled?

Im waiting to hear back from a couple tank manufactueres about the tank cost/installation

I would get pods in there as soon as there's water. I believe that is what most people do. My 8' x 4' x 20" was $5k USD and around another 1k for the stand/moving crew. Just to give you an idea.

 

[14crazychris]

I would get pods in there as soon as there's water. I believe that is what most people do. My 8' x 4' x 20" was $5k USD and around another 1k for the stand/moving crew. Just to give you an idea.

Okay cheers! Yeah I have a rough idea, I'm from the UK so maybe pricing will be slightly different. Depending on what I'm quoted a may add another 6 inches to the length. Once I've got a date planned for the build I can start accumulating stuff and get things ticked off the list. This thread has been very helpful though so far!

 

[WheatToast]

Thank you so much for all of that information you provided, I can see you went to some effort to put that reply together and those links are great! Just what I needed to have a look at!

Id rather not keep any super sensitive species so might have to give the rays and the horn shark a miss (even though the horn was my favourite lol) , especially as my current tropical tank reaches 27/28 degrees in peak summer here. The blue spot is lovely but sounds like it could be quite demanding, I think sticking to one epaulettes and a couple cat sharks would be more suitable.

No problem! The yellow stingray (Urobatis jamaicensis) you mentioned earlier doesn't seem too terribly difficult to care for (when it comes to elasmobranchs) and comes from warmer waters so if you really want a ray but don't have any other choices besides the ones you have listed, this is the one to choose. There are other bullhead sharks (Heterodontus sp.) besides the horn shark that inhabit warmer waters, though these have become increasingly rare.

I have a friend who has a nice red macro algae growing well in their sump but I havnt identified the species yet.

Pictures?

As for groupers I was looking at the coral grouper and a blue line. I really like the panther grouper but looks like it will get quite large and add considerably to the bioload. Any other groupers suggested to look over?

No grouper suggestions, personally, but from some quick research, the first two look very gorgeous, albeit quite aggressive. Others might have better advice on these fish.

Yeah I have some 2 foot long stainless steel tongs which I can use...

I would be cautious about using metal, even stainless steel, especially in an elasmobranch tank. I think it messes with their Ampullae of Lorenzini, though again, others might know better.

I would get pods in there as soon as there's water. I believe that is what most people do. My 8' x 4' x 20" was $5k USD and around another 1k for the stand/moving crew. Just to give you an idea.

+1
Amphipods are great "pod" scavengers but copepods are still part of a healthy tank ecosystem.

 

[14crazychris]

No problem! The yellow stingray (Urobatis jamaicensis) you mentioned earlier doesn't seem too terribly difficult to care for (when it comes to elasmobranchs) and comes from warmer waters so if you really want a ray but don't have any other choices besides the ones you have listed, this is the one to choose. There are other bullhead sharks (Heterodontus sp.) besides the horn shark that inhabit warmer waters, though these have become increasingly rare.

Pictures?

No grouper suggestions, personally, but from some quick research, the first two look very gorgeous, albeit quite aggressive. Others might have better advice on these fish.

I would be cautious about using metal, even stainless steel, especially in an elasmobranch tank. I think it messes with their Ampullae of Lorenzini, though again, others might know better.

+1
Amphipods are great "pod" scavengers but copepods are still part of a healthy tank ecosystem.

Great, I’ll have a look into the yellow ray and see how obtainable it is in my area, I do love my freshwater rays and it would be nice to have a saltwater counterpart. I’ll also take a look at the bullhead sharks but if these are rare its probably going to be a no go. I’ll get some pictures tomorrow, I’ll keep surfing google to find it.

My heater is a titanium heater, will that be a problem in the shark tank? I was planning to get another to keep temps stable.

Brill, will add the pods to my list!

 

[14crazychris]

No problem! The yellow stingray (Urobatis jamaicensis) you mentioned earlier doesn't seem too terribly difficult to care for (when it comes to elasmobranchs) and comes from warmer waters so if you really want a ray but don't have any other choices besides the ones you have listed, this is the one to choose. There are other bullhead sharks (Heterodontus sp.) besides the horn shark that inhabit warmer waters, though these have become increasingly rare.

Pictures?

No grouper suggestions, personally, but from some quick research, the first two look very gorgeous, albeit quite aggressive. Others might have better advice on these fish.

I would be cautious about using metal, even stainless steel, especially in an elasmobranch tank. I think it messes with their Ampullae of Lorenzini, though again, others might know better.

+1
Amphipods are great "pod" scavengers but copepods are still part of a healthy tank ecosystem.

The macro algae is

Gracilaria Curtissae​

 

[Jay Hemdal]

Great to know! The bamboo is crossed off the list! Judging by the responses so far the epaulettes and coral cats seem to be the winners I think I will end up with. Do the females tend to get larger? Would all males or all females be best? Also is it advisable to purchase them in egg form or fully developed? Is this purely down to owners choice or are there any positive and negatives to this?

yes Bumblee bees are definitely a big no! More looking at the coral grouper and blue line unless anyone has suggestions of some others to look at?

thank you

Shark eggs have a hatch failure rate, so buying newly hatched young is often better. Females are typically larger than males. However, I've had male epaulettes fight. Coral catsharks are better in that regard.

Jay