Bending the rules of minimum aquarium size?

[DalPal25]

Hey everyone, I have a couple questions about fish keeping.

So how does everyone find out what size tank a fish needs? Obviously some of them are common knowledge (tangs) but what resource does everyone else use when learning about a new fish? I look on live aquaria and read a lot of reef keeping books and a lot of them have different answers? For example, in one of my books it says a Flame Angel would be fine in a minimum 20 gallon. That seemed a little small to me but then again I am new to this. On live aquaria it says 70 gallons. Do you all just post here to find out these answers? What resource do I trust?

And another question: is there anyway to bend these rules a little? I know a lot of it has to do with swimming space but what if you gave a fish its own tank that is a little smaller than whats recommended for that species but it had no other fish in it so the swimming space belongs entirely to that one fish? Does that have any sort of factor?

Thanks in advance to anyone who helps me answer these questions.

 

[DeniseAndy]

I think there are some sources on here about that. May want to do a search for fish tank size.

Also, a big factor comes into deciding when you take the fishes natural habitat into account. For example, tangs swim a lot. They need long stretches of space because in the wild they travel long distances. Now clownfish generally stay in a small area once being hosted by an anemone. Shrimp gobies and shrimp along with some jawfish stay in a relatively small area once they find the burrow area they want.

This is all a factor of space. Make sure not just to look at tank requirements but to factor in behaviors.

 

[reeferfoxx]

Keep in mind, for example, the flame angel will do fine in a 20 gallon by itself. But with other fish, you might want something larger. A lot also has to do with bio-load. But as websites like nano reef teach us, it is ok to put 6 fish in a 10 gallon tank. So that 20 gallon could hold 12 fish.

 

[jeremy.gosnell]

On the flame angel issue and 20 gallon tank is mighty small for a flame angelfish, by itself or otherwise. LiveAquaria's suggestion is more accurate, but a 55 gallon tank would serve a flame angelfish just fine. There are a lot of issues to take into account when determining what size fish can fit into a tank. One is the fish in questions eating habits. Does it eat live food, prepared, is it herbivorous? This can give you some idea of how much waste a fish produces and how much waste their food will produce. Believe it or not, herbivorous fish produce more waste than live-food eating ambush predators that only need fed once or twice a week. The goal is to offer the fish amble space and appropriate tank conditions, while also using filtration to maintain clean water.

If you push a tank to the stocking limits you're often setting up for a long-term disaster. Overstocked tanks are prone to fatal disease outbreaks, water-quality/chemistry imbalance and often fare very poorly in the face of a power outage or equipment failure. What species are you considering? It would be easier to provide advice on what size tank it needs, rather than a blanket rule for stocking a marine tank.

 

[Lionfish Lair]

All of the recommendations are opinions. There's no actual number for any fish and it should be used as a guideline, not an absolute.

 

[zoomonster]

I think the one bit of data you can rely on from fish listings at places like LA/DD is the fish maximum size to make decisions. Recommended tank size is just that... a recommendation. When things were more primitive the recommendation was 1" of fish per 5g of tank size (then again the min recommended tank size was 55g for salt) . With better equipment now and good practices you can easily push that 2-4x. I've not measured fish but I'm probably well over 3x in my tank and I keep SPS/LPS/soft. I tend to like variety so I've always preferred smaller fish so I can have more. Excluding tangs, butterflys and some wrasses most "reef safe" fish fall into that category. I do keep 3 tangs and a copperband butterfly in my 200 but that's it for "big" fish. The rest are dwarf angels, anthias, wrasses, dottybacks and clowns.

 

[reeferfoxx]

Just use your moral compass. Google what the ocean looks like then google what a 20 gallon looks like and then dwell on the thought of what mankind is doing.

 

[DalPal25]

Just use your moral compass. Google what the ocean looks like then google what a 20 gallon looks like and then dwell on the thought of what mankind is doing.

well this made me feel like I shouldn't have ANY fish

 

[reeferfoxx]

well this made me feel like I shouldn't have ANY fish

Well, I didn't mean to make it that dramatic. I was just giving a perspective what people are doing to the lives a fish had. I am all for having fish as long as they are comfortable. If someone took you from your home and put you in a 8x8 cell, what that be exciting for you? At least give them a home where their natural behaviors can thrive.

 

[DalPal25]

Well, I didn't mean to make it that dramatic. I was just giving a perspective what people are doing to the lives a fish had. I am all for having fish as long as they are comfortable. If someone took you from your home and put you in a 8x8 cell, what that be exciting for you? At least give them a home where their natural behaviors can thrive.

hahaha I know, I understood what you meant completely.

 

[Lionfish Lair]

Yet many feel that way about our entire hobby.

 

[DalPal25]

On the flame angel issue and 20 gallon tank is mighty small for a flame angelfish, by itself or otherwise. LiveAquaria's suggestion is more accurate, but a 55 gallon tank would serve a flame angelfish just fine. There are a lot of issues to take into account when determining what size fish can fit into a tank. One is the fish in questions eating habits. Does it eat live food, prepared, is it herbivorous? This can give you some idea of how much waste a fish produces and how much waste their food will produce. Believe it or not, herbivorous fish produce more waste than live-food eating ambush predators that only need fed once or twice a week. The goal is to offer the fish amble space and appropriate tank conditions, while also using filtration to maintain clean water.

If you push a tank to the stocking limits you're often setting up for a long-term disaster. Overstocked tanks are prone to fatal disease outbreaks, water-quality/chemistry imbalance and often fare very poorly in the face of a power outage or equipment failure. What species are you considering? It would be easier to provide advice on what size tank it needs, rather than a blanket rule for stocking a marine tank.

I didn't have just one idea of one fish when I posted this. Was mainly just wondering what is a trustworthy guideline. Although I am curious about whether a one spot Foxface would be fine in a 45-50 gallon. Live Aquaria says 70gal minimum but they also say the same thing for a flame angel and I've seen plenty of flames in much smaller tanks.

 

[reeferfoxx]

I didn't have just one idea of one fish when I posted this. Was mainly just wondering what is a trustworthy guideline. Although I am curious about whether a one spot Foxface would be fine in a 45-50 gallon. Live Aquaria says 70gal minimum but they also say the same thing for a flame angel and I've seen plenty of flames in much smaller tanks.

Someone here has a one spot foxface in a 45 gallon. Can't for the life of me remember who.

 

[Lionfish Lair]

You kind of got to peruse a few different trusted sources.

 

[reeferfoxx]

The only trusted source is knowing their habitat. The rabbit fish has the ability to camouflage itself in extreme cases and they prefer hiding places. So if you can achieve a habitat with a lot of live rock for hiding and algae to eat, they should feel comfortable. Otherwise...ich lol

 

[Deinonych]

I've found LiveAquaria's tank size recommendations to be consistently good. At the end of the day, any tank is going to be smaller than the fishes' natural habitat (i.e. the ocean), so it will never be truly ideal. The key is to give the fish the best care possible.

 

[Valkyrie]

Yet many feel that way about our entire hobby.

I try to remind myself that it's poor fish keeping practices that give the hobby a bad name. You're not going to change the anti's minds because the bad fish owners outweigh the good.
The best thing we can do is everything we can for the creatures we've chosen to take into our homes. Give them a good life. Love them. Give them what they can't get in the ocean, like safety from a predator gobbling them up. We aren't the people cutting off shark fins and leaving the sharks to die a miserable death. People need to learn how to choose their battles. But they won't. :mad:

 

[DalPal25]

I try to remind myself that it's poor fish keeping practices that give the hobby a bad name. You're not going to change the anti's minds because the bad fish owners outweigh the good.
The best thing we can do is everything we can for the creatures we've chosen to take into our homes. Give them a good life. Love them. Give them what they can't get in the ocean, like safety from a predator gobbling them up. We aren't the people cutting off shark fins and leaving the sharks to die a miserable death. People need to learn how to choose their battles. But they won't. :mad:

Not to mention that we give them food in a timely manner. I know for a fact fish aren't getting spot-fed in the ocean!

 

[Robink]

I cheat and always check a fish's tank requirement on Liveaquaria...

 

[Brautumn]

I didn't have just one idea of one fish when I posted this. Was mainly just wondering what is a trustworthy guideline. Although I am curious about whether a one spot Foxface would be fine in a 45-50 gallon. Live Aquaria says 70gal minimum but they also say the same thing for a flame angel and I've seen plenty of flames in much smaller tanks.

I have seen a one spot foxface in many sizes and some were to big for the tank (55g) and just zoomed back and forth but was full size. We had one in our 75g and noticed a change in his habits once he got bigger and we transferred him to our 120g and what a difference. So, if you have to have one get a baby and plan when he gets to big. You will know when a fish is not happy.