How many fish per gallon???

[Picasso]

I keep telling my daughter (16) that she's got too many fish in her tank. 14 gallon bio-cube with two tiny clowns and two (butt-ugly) Pajama fish? Look like fresh water angels with demonic red eyes. She's got a cleaner shrimp and an emerald crab along with a bunch of hermits and snails. I think if you lined all the fish up along a ruler you would have about 7 inches total. She's got one mushroom coral. Her numbers are ok, but the butt-ugly fish look stressed to me, not that I would know what a stressed butt-ugly fish would look like). After the anemone fiasco, I don't want to stress out her fish, but I don't want to nag and make her hate her aquarium. Should I keep trying to have her get rid of a couple of fish?

thanks,
Catherine

 

[d2mini]

You could buy her a bigger tank. :mrgreen:

I wouldn't put two of anything in that tank.
My 48 only has one small clown, one firefish, one 6-line wrasse, one cleaner shrimp and a small cleanup crew. I plan on putting in another couple small fish and that's it.

In a 14g nano I would probably have one small clown, and then one or maybe two other SMALL fish. A goby or blenny would be good. No more than that. Definitely no anemone.

 

[daugherty]

to many fish the round about ratio is 1in per 5 gal. a 1 clown is to bug for a 14 gallon tank let along two of them and two other fish.

 

[Teixeira29]

I wouldnt put anything else in the tank. If you put to many fish in the tank, the fish would make to much waste and your chemicals could become to high.

 

[fishsticks]

yea its about 1 inch of fish per 5gallons, u also have to consider how big your fish will get and giving them room to grow. and it also depends on your water quality and what u do to keep down your trates. if u buy a clwn thats 1 inch estimate how big he will get around 2-3 inches max over a couple of years ofcourse. second if your up on ur water changes and or have a protein skimmer u can add 1 or 2 more extra fish without putting your tank at risk. me example i have a 30 gallon bio. i should have nomore than 4 fish but i currently have 6 and they r all about 1 1/4 of an inch well over my bioload and considering in the next 3 years they will all get an extra 1/4 to 1/2 inch in length... but im good in water quality cuz i do big waterchanges every 2 weeks...so i can handle them, its sometimes up to the person him/herself to keep up good waters in order to push the limit just a tad or stick with the rule of thumb 1inch = 5gallons

 

[yote]

The cardinals probably are stressed.They really shouldnt be in anything less than a 55.

 

[Fitz]

Way too many fish for a 14 gallon bio cube. The rule should be no more than 1" of adult fish per 5 gallons of water. Keep in mind that, once you add substrate, rock, ornaments, etc. you no longer have 14 gallons of water. Also, always error on the side of caution. So the calculation should look like this:

14 x .125 = 1.75
14 - 1.75 = 12.25

In the above calculation .125 is the percentage of water volume taken up by substrate, rocks, and ornaments. So in the case of a 14 gallon tank, you want to subtract 1.75 gallons from the total water volume.

This leaves you with 12.25 gallons of water. Keeping the 1" per 5 gallons rule in mind, we must now divide this by 5.

12.25 / 5 = 2.45
Round this to the nearest half inch, gives you a maximum of 2.5" of adult fish. IF you have a protein skimmer, you can increase your bio load by 20%; otherwise, you'll want to stay at 2.5.

To sum it up, a 14 gallon bio cube should have no more than:

2.5" of fish without a protein skimmer, or
3" of fish with a protein skimmer.

Keep in mind, these numbers represent the total fish length at adulthood.

 

[Bifferwine]

This thread is 3 1/2 years old.

 

[Fitz]

This thread is 3 1/2 years old.

I took notice of that. However, that does not mean others will not find the information to be helpful should they stumble across the thread just as I had.

 

[cvcdrk]

lol 2009

Living Reefs needs an archive feature so that these topics are still sortable and searchable but you can't make new posts in them. :-)

 

[BL1]

I took notice of that. However, that does not mean others will not find the information to be helpful should they stumble across the thread just as I had.

Even if that were so, there is no way a math formula can be made to tell you how many fish you can have. Where did you get your numbers that you used from? Theyre pretty off if you ask me. By your calculations for my 75 that would mean 75 x .125 = 9.375, 75 - 9.375 = 65.625, 65.625 / 5 = 13.125. That means I can only have 3 4" fish in my tank?

 

[cvcdrk]

Better start selling off some of those fish! :-P

 

[yote]

Besides that. You can't go the size of the fish alone. You have to consider the species of fish your keeping. Some are more aggressive, some cause more waste, some just like to find a place to sit and watch. All that has to be considered too.

 

[Fitz]

This thread is 3 1/2 years old.

Even if that were so, there is no way a math formula can be made to tell you how many fish you can have. Where did you get your numbers that you used from? Theyre pretty off if you ask me. By your calculations for my 75 that would mean 75 x .125 = 9.375, 75 - 9.375 = 65.625, 65.625 / 5 = 13.125. That means I can only have 3 4" fish in my tank?

Brian,

There are many more things to take into consideration with your 75 gallon tank that do not apply to the bio cube. For starters, I'm assuming you have filtration under the tank? Which probably consists of some sort of sump? If so, the volume of the sump can be added in to your total volume. This may even be enough to cancel out the 10 - 15% (in my calculations I use .125 which represents 12.5%) of water volume lost to such things as substrate, rock, and various aquarium ornaments. On a tank of your size, we must also look at the type of filtration you are using. Do you have a protein skimmer? Refugium? Bio balls? UV sterilizer? Etc. We must also look at the shape of the tank and the total surface area so we can factor in the oxygen exchange. All of this comes into play and can significantly affect your total bio load. Also keep in mind that fish are generally measured from the mouth to the base of the tail fin. Without knowing your exact setup, the type of fish you have, and the frequency and size of your water changes, I can't say how many 4" fish I would recommend.

I hope this helps clear up any misunderstandings.

~Fitz

 

[ErinCahir]

Brian,

There are many more things to take into consideration with your 75 gallon tank that do not apply to the bio cube. For starters, I'm assuming you have filtration under the tank? Which probably consists of some sort of sump? If so, the volume of the sump can be added in to your total volume. This may even be enough to cancel out the 10 - 15% (in my calculations I use .125 which represents 12.5%) of water volume lost to such things as substrate, rock, and various aquarium ornaments. On a tank of your size, we must also look at the type of filtration you are using. Do you have a protein skimmer? Refugium? Bio balls? UV sterilizer? Etc. We must also look at the shape of the tank and the total surface area so we can factor in the oxygen exchange. All of this comes into play and can significantly affect your total bio load. Also keep in mind that fish are generally measured from the mouth to the base of the tail fin. Without knowing your exact setup, the type of fish you have, and the frequency and size of your water changes, I can't say how many 4" fish I would recommend.

I hope this helps clear up any misunderstandings.

~Fitz

I think this is what we're all trying to say. Without knowing (and even WITH knowing) there is no formula that can tell you how many fish you can have. Sure there are guidelines, but it's not an exact science.

 

[Fitz]

I think this is what we're all trying to say. Without knowing (and even WITH knowing) there is no formula that can tell you how many fish you can have. Sure there are guidelines, but it's not an exact science.

Erin,

You're exactly right which is why I said in my original post that I was speaking in terms of a 14 gallon bio cube and erroring on the side of caution. Unfortunately, people often only hear what they want. That's ok though... As long as it leads to a healthy discussion. Flaming is not acceptable on any forum.

What irritated me is that the moderators did not seem to like the fact that I responded to a 3 1/2 year old thread. If that is an issue on this forum, then threads should be closed for discussion after a "reasonable" amount of time... 90 days? 6 months? I'm not sure how to define reasonable in this case.

 

[ErinCahir]

I wasn't flaming you. And I still stand by what I said. Even in biocubes each tank is still different. There are mods you can make, not everyone has the same amount of live rock/hiding places, and fish personalities themselves come into question.

Now, I don't know why the threads aren't closed after a certain amount of time, but it's kind of an unspoken rule that old threads don't get commented on. I know this is different from other forums, but this is a different kind of forum. :)

 

[Fitz]

I didn't mean to imply that you or anyone else was flaming me. I was just simply saying that a healthy discussion or debate is a good thing... as long as people respect each others opinions. I'm glad you stand behind what you said; I stand behind my original post as well. When responding to a thread, I am simply sharing my experience. Obviously, everyone is going to have different experiences with different setups and one should realize that advice of this nature should be taken as a guideline. I was just sharing what has worked for me through trial and error over my 10+ years in the hobby.

I will say though that I do use a mathematical equation for deterimining how many fish to keep in my tanks. That equation takes my filtration (sump, refugium, UV sterilizer, protein skimmer, etc.), regular tank maintenance, tank size, surface volume, fish types, "clean-up crews", etc. into account. I basically give everything a weight which I factor into my equation. This method may not be perfect and may not work for everyone, but it works for me and has proven to be very successful in my experience.

In a 75 gallon tank, I personally would have no more than 8 - 10 fish depending on the types... Less if I had aggressive fish, like a tank full of Trigger fish.

This is based off of my experience and what has worked for me over the years and should be used only as a guideline.

:)

 

[ErinCahir]

Guideline. That's the most important word there. :)