The invert-only reef tank -- who needs fish?

[davidcalgary29]

I've just added two fish to my Reefer 350 after a 72-day fallow period after *some* disease wiped out the tank in early August. If the disease re-emerges, I've been thinking of just keeping inverts and cultivating coral in my tank. Does a tank really need fish to be considered a reef tank? I think a tank with a cornucopia of inverts, coral, and macro could be just as arresting. After all, I noticed that my shrimp were much less cryptic without any fish in the tank, and often strutted around in full view, all day long. They've since retreated to the back of the tank with the reintroduction of fish.

Has anyone converted their main display to a tank that's invert-only?

 

[i cant think]

I've just added two fish to my Reefer 350 after a 72-day fallow period after *some* disease wiped out the tank in early August. If the disease re-emerges, I've been thinking of just keeping inverts and cultivating coral in my tank. Does a tank really need fish to be considered a reef tank? I think a tank with a cornucopia of inverts, coral, and macro could be just as arresting. After all, I noticed that my shrimp were much less cryptic without any fish in the tank, and often strutted around in full view, all day long. They've since retreated to the back of the tank with the reintroduction of fish.

Has anyone converted their main display to a tank that's invert-only?

I have never tried it - It would definitely be an unusual tank though, I think you would still need to do all the basic stuff with fish (Feed, water change ect..) mostly because the nutrients would have to be built up for coral food along with inverts being able to scavenge the rocks for food.

 

[ariellemermaid]

I have never tried it - It would definitely be an unusual tank though, I think you would still need to do all the basic stuff with fish (Feed, water change ect..) mostly because the nutrients would have to be built up for coral food along with inverts being able to scavenge the rocks for food.

What we really need is to come up with a catchy name for this type of tank like FOWLR. Ours is a 20g we set up to QT inverts and corals. We didn’t set it up as a frag tank but instead a full reef just with some magnetic frag racks. We call it our crab tank. Cool crabs get lost in even 40g tanks, but in there we can enjoy little pom poms, conch’s, acropora crabs, and shrimp. Interestingly, despite usually feeding only a little square of nori a day nutrients aren’t a problem. In fact we can only keep them under control with water changes. I don’t even know where they come from. Corals have thrived in there that languished in the 40g with fish for whatever reason.

I think the limitation is size. I mean it would be fine to have a large tank filled with corals, but if you really want to enjoy crabs it’s a tank that needs to be small, and you enjoy it from a chair directly in front. Even then, it’s hard to find our favorite crabs at times. I will also say we’ve had a fair amount of crab turnover, so without more to scavenge they might not be getting enough food. Then again, no one talks about their 10 year old crab so maybe they just don’t do that well long term in captivity, I’m not sure. I have however seen plenty of pictures on here of coral filled tanks with just 1-3 fish, so I think people are doing this, just not a whole lot with zero fish.

 

[i cant think]

What we really need is to come up with a catchy name for this type of tank like FOWLR. Ours is a 20g we set up to QT inverts and corals. We didn’t set it up as a frag tank but instead a full reef just with some magnetic frag racks. We call it our crab tank. Cool crabs get lost in even 40g tanks, but in there we can enjoy little pom poms, conch’s, acropora crabs, and shrimp. Interestingly, despite usually feeding only a little square of nori a day nutrients aren’t a problem. In fact we can only keep them under control with water changes. I don’t even know where they come from. Corals have thrived in there that languished in the 40g with fish for whatever reason.

I think the limitation is size. I mean it would be fine to have a large tank filled with corals, but if you really want to enjoy crabs it’s a tank that needs to be small, and you enjoy it from a chair directly in front. Even then, it’s hard to find our favorite crabs at times. I will also say we’ve had a fair amount of crab turnover, so without more to scavenge they might not be getting enough food. Then again, no one talks about their 10 year old crab so maybe they just don’t do that well long term in captivity, I’m not sure. I have however seen plenty of pictures on here of coral filled tanks with just 1-3 fish, so I think people are doing this, just not a whole lot with zero fish.

I think many people are more interested in the fish and coral aspect and so, not many people have 10+ year old crabs - I certainly don’t with the Jade and Radiant wrasses I currently have.

 

[davidcalgary29]

What we really need is to come up with a catchy name for this type of tank like FOWLR. Ours is a 20g we set up to QT inverts and corals. We didn’t set it up as a frag tank but instead a full reef just with some magnetic frag racks. We call it our crab tank. Cool crabs get lost in even 40g tanks, but in there we can enjoy little pom poms, conch’s, acropora crabs, and shrimp. Interestingly, despite usually feeding only a little square of nori a day nutrients aren’t a problem. In fact we can only keep them under control with water changes. I don’t even know where they come from. Corals have thrived in there that languished in the 40g with fish for whatever reason.

I think the limitation is size. I mean it would be fine to have a large tank filled with corals, but if you really want to enjoy crabs it’s a tank that needs to be small, and you enjoy it from a chair directly in front. Even then, it’s hard to find our favorite crabs at times. I will also say we’ve had a fair amount of crab turnover, so without more to scavenge they might not be getting enough food. Then again, no one talks about their 10 year old crab so maybe they just don’t do that well long term in captivity, I’m not sure. I have however seen plenty of pictures on here of coral filled tanks with just 1-3 fish, so I think people are doing this, just not a whole lot with zero fish.

I seem to be collecting big inverts in this tank, so visibility shouldn't necessarily be a problem: molluscs can be surprisingly large as they track across glass and landscape, so I tend not to have to hunt them out. My all-black keyhole limpets (aka "elephant slugs") are as attractive as any all-black fish that I've seen.

I agree that upkeep will be much the same, although I don't have that much coral and am not actively seeking to build an impressive SPS tank. I've now managed to source a fire urchin, and am probably going to have to keep up with the supplemental algae feedings as much as I would if the tank was filled with tangs.

 

[Tamberav]

I've just added two fish to my Reefer 350 after a 72-day fallow period after *some* disease wiped out the tank in early August. If the disease re-emerges, I've been thinking of just keeping inverts and cultivating coral in my tank. Does a tank really need fish to be considered a reef tank? I think a tank with a cornucopia of inverts, coral, and macro could be just as arresting. After all, I noticed that my shrimp were much less cryptic without any fish in the tank, and often strutted around in full view, all day long. They've since retreated to the back of the tank with the reintroduction of fish.

Has anyone converted their main display to a tank that's invert-only?

Yep! Always throught it would be a cool tank. Many different small inverts you could more safely add without fish too like Peterson shrimp and then will be hosted by nems. You can use rock flower nems or mini carpets if you want something that takes up less real-estate than a BTA. Acro crabs and anemone shrimp are also very cool. They make some more colorful pistol shrimp that do not pair with fish.

Also an all invert tank can probably go lidless all the time for that sweet look. No fish to jump out. Inverts typically don’t just randomly come flying out like fish.

 

[ariellemermaid]

Yep, lidless here. Although it’s impressive how shrimp can jump if you chase them with a net! Otherwise they stay where they’re supposed to be.