Fish Tank Stocking Levels – Freshwater Tropical

[dgwebster]

A lot of the time we often see the same question being asked on this forum;

How much fish/Are these fish ok in this tank?

The first one is obvious, the second one is often replied with “i wouldn't get a clown loach in that 1ft corner tank” or such type.

So here is my own personal definitive guide to fish tank stocking levels and how to calculate and decide what it is for your tank. It is based on previous polls I have done, reading of a number of books and speaking to a number of people. This particular post is restricted to TROPICAL FRESHWATER and does not cover coldwater or marine tanks, which have different criteria.

It does not cover every situation and you should always always also use a bit of common sense.

First there are three general ways to get a “rough guide” stocking level.

• Method 1: Surface area (length x width) divided by 10 (e.g. A 48”x12” tank = 576/10= 56.7 inches.)
• Method 2: Surface area divided by 12.
• Method 3: 1 inch of fish per 1 gallon of water

*All measurements should be done in inches, or convert ALL numbers appropriately to cm.

This gives you a general stocking level. This is where you then need to start considering your fish and which method to use.

If you are keeping fairly small (say 3”-4” and under fish) community fish that are not aggressive, Method 1 will be your best method.

If you are keeping again, community fish or species only tank (that you can keep multiple of the species of) – and you can include larger ones this time - that are not aggressive and a little bit more messy, Method 2 is your better calculator. It gives that bit more for the size of the fish, and it gives that bit more for the mess that can be made by the fish.

If you are keeping extremely messy or aggressive fish, Method 3 is your better method. However, as with all aggressive fish, check out the particular fish you wish to keep, you may need to adjust this rule and give it more room.

Once you have established your method, you need to pick your fish. This is where the common sense comes in,. I hope you have some. There is some simple items you need to consider:

• You need to ensure that you stay within your guideline.
• You then need to research each fish, make sure they can all live together.
• Consider the size of the fish to the tank. I.e. You may get 12” in the stocking guideline, but that does not mean buy a 12” or 6” or even probably a 4” fish. Imagine yourself as the fish in the tank (I'm serious). If you can feel the glass within inches of you, forget it. If you are being an active hyper fish, if you cant swim more than 5x your body length, forget it. Use your imagination and be nice.
• Consider aggressiveness and adjust accordingly.
• Consider the “level” your fish are taking up. This is especially true for Method 1 or Method 2 – although you can get 100” of fish, getting all 100” as bottom feeders is not right. Try to balance a third bottom, a third middle, a third top. Or 25% All, 25% Top, 25% Middle, 25% Bottom.

This is what I consider when purchasing fish for my tank.

There is one final piece of advice, and this is a very personal one:

I feel that you should NOT purchase fish that grow bigger than your tank with the opinion of “I'll get a bigger tank when it needs it.” Do not buy unless you can house the adult fish size NOW.

 

[Bloo]

Am I missing something ? Because I was under the impressions that the 1" per gallon guideline was only ever applied (loosely) to small slim bodied fish that won't reach more than a few inches in adulthood ?
Yet you are applying it to extremely messy or aggressive fish

And that anything larger, messier requires even more ?

 

[Qays]

Doesnt it depend on your filteration too?

Good post though!

 

[clareriley]

I dont agree, I keep malawi Cichlids and I am overstocking to reduce aggresion not understocking with 2 filters so I am very overfiltering. I think the 1inch per gallon rule should be used to a average community freshwater aquarium with average fish in with average filtration. Plus this also depends on water changes and such and such.

 

[Tolak]

I think people are missing the point of this topic; it's in the Beginner Questions section.

I don't stock like this, I break every rule, but I did stock similar to this at first. I think this topic is a good idea for trying to cut down on the "Do I have too many fish, how many fish can I have?" topics. I've noticed these questions usually involve livebearers, corys, and danios. They also involve average filtration. These stocking suggestions would apply.

"It does not cover every situation and you should always always also use a bit of common sense." If someone has questions on more advanced stocking, such as Africans or N.W. cichlids, they will more than likely ask in that particular section.

 

[tia123]

I think people are missing the point of this topic; it's in the Beginner Questions section.

I don't stock like this, I break every rule, but I did stock similar to this at first. I think this topic is a good idea for trying to cut down on the "Do I have too many fish, how many fish can I have?" topics. I've noticed these questions usually involve livebearers, corys, and danios. They also involve average filtration. These stocking suggestions would apply.

"It does not cover every situation and you should always always also use a bit of common sense." If someone has questions on more advanced stocking, such as Africans or N.W. cichlids, they will more than likely ask in that particular section.

i understand you must get fed up with people asking the same question about how many fish can i have etc ? but for us who are new to fish keeping, its nice to make sure we are not geting it really wrong. i read your post and have taken it all in - thanks, but dont be to hard on us new ones who only want to know if the particular fish we have in our tanks are suitable - we all have to start sumwhere

 

[clareriley]

i understand you must get fed up with people asking the same question about how many fish can i have etc ? but for us who are new to fish keeping, its nice to make sure we are not geting it really wrong. i read your post and have taken it all in - thanks, but dont be to hard on us new ones who only want to know if the particular fish we have in our tanks are suitable - we all have to start sumwhere

I would rather peeps start a thread and ask than go off a cookie cutter on some site. then they have the opinions of many. Tia, you are right that you shouldnt be discouraged from asking any question. This is what the forum is for. If someone doesnt want to answer your post then they can skip it but there are loads of members that have been fish keeping for years and that enjoy helping newbies with the smallest of questions.

 

[tia123]

i understand you must get fed up with people asking the same question about how many fish can i have etc ? but for us who are new to fish keeping, its nice to make sure we are not geting it really wrong. i read your post and have taken it all in - thanks, but dont be to hard on us new ones who only want to know if the particular fish we have in our tanks are suitable - we all have to start sumwhere

I would rather peeps start a thread and ask than go off a cookie cutter on some site. then they have the opinions of many. Tia, you are right that you shouldnt be discouraged from asking any question. This is what the forum is for. If someone doesnt want to answer your post then they can skip it but there are loads of members that have been fish keeping for years and that enjoy helping newbies with the smallest of questions.

thanks for that clare, my comment wasnt directed at ev1, i know there are many helpful people here. didnt want to upset any1, i just tend to speak my mind.

 

[Bloo]

I think people are missing the point of this topic; it's in the Beginner Questions section.

So in the beginners section we give advice that it's ok to stock far beyond the 1" per gallon guideline ? Not only that, but also say that it's OK for extremely messy or aggressive fish ?

I don't agree with that at all. I think with experience you can break and play with those guidelines when you know where you have more room for potential error. I think it's absolutely vital that we encourage (average community fish) under stocking rather than overstocking.

African cichlids are of course a whole other ball game and this does not apply to them.

 

[geo7x]

Method 1: Surface area (length x width) divided by 10 (e.g. A 48”x12” tank = 576/10= 56.7 inches.)

I dont follow, 56.7 inches? is that 56.7 inches of fish or what?

 

[dgwebster]

well pointed out geo7x, will amend that.

Bloo, the suggestions I have given above are those supported by a majority. from having a poll to Most places [EDIT] one can get information [end of edit] suggest (esp in beginner books and sites) that method 1 should be used. That is the most stocking of a tank for starting off with.

As also mentioned, you can put more in, and certainly with some fish, you MUST put less in. I personally am overstocked, but now experienced enough and filtered enough for the bioload to be ok, and I've not overcrowded. Thats something that comes with a bit more time and experience or even possibly research and thought though.

the 1" of fish per gallon is the LEAST stocking out of all three. for example, a 2ftx1ft tank would get nearly 29" by method 1, but 15" by 1" per gallon method 3. seems like it properly fits for the more messy (taking up the extra filtration) fish. I also mention considering the specific fish in question you have in mind. but the general rule of thumb can be used.

Its not meant to be an ends all answer, its for the beginner to give an IDEA of how much they can be stocking by. I also agree, questions should still be asked, because if you have a question or are unsure, you should not be doing anything. and just to get opinion as well. Its here to help get some people started, give them a place to start when thinking about what fish, how many etc. When they have a stocking idea, post. if you still have a question about how much to stock, post.

I think its been taken too seriously as a "bugger off and stop asking this. this is gospel, follow it or the hand of God will Smite you". It is here to give thought and help answer one of the most commonly asked questions.

 

[Tolak]

It's not so much as getting fed up with answering beginner's questions, I have no problem with that. I think it's more a case of having something to guide a beginner before they consider going out & buying all the gear they think they need for the desired setup they are thinking of.

It's the old those that fail to plan plan to fail thing. This is more of a planning tool than anything else. Also, I, as most others I know, can read much faster than they can type. Something of this sort makes it easier for a beginner to get a handle on stocking, while they try to get a handle on cycling, water changes & conditioning, and probably a dozen other things I don't think of as they come as second nature at this point.

I don't think there is one definite answer to most anything concerning aquatics, weather it's stocking, cycling, filtration, whatever.

 

[dgwebster]

very well put tolak. it also helps for those in the opposite situation - find themselves with something, but no idea what they can put in it.

 

[Bloo]

the 1" of fish per gallon is the LEAST stocking out of all three. for example, a 2ftx1ft tank would get nearly 29" by method 1, but 15" by 1" per gallon method 3. seems like it properly fits for the more messy (taking up the extra filtration) fish. I also mention considering the specific fish in question you have in mind. but the general rule of thumb can be used.

Exactly - and that's a very large number of fish for a beginner to deal with on top of the usual cycling of tanks that's generally on a beginners plate as well. Sorry to disagree because obviously you've put time and effort into composing this, but I don't feel comfortable recommending these things to the very beginners.

 

[dgwebster]

I dont know, it ultimately goes by what they are getting. e.g. 29 neons - no. but if they were purchasing a couple of dwarf gouramis, maybe a half dozen something else and another half dozen something else, why not? thats not too much IMO unless there is a personal feeling/thought behind it (e.g. If I were getting for someone with special needs, I would not stock like this) But again, thats where the recommendation of consideration for the fish and the use some common sense comes in.

Its also a recommended maximum and doesnt advise to put them all in at one time. Once there is experience and keeping alive this kind of number, then maye think about overstocking etc.

and then again, I call dwarf gouramis messy fish OMG i never seen fish like that poop like that