How Many Fish Can I Put In My Tank

[RBurkett]

Hi,

I know there is a rule of so many mm of fish to so much sq inch of tank. {or something like that}

But in simple terms for people like me, I have a 60L tank and like Tetras, Molly and Betta fish. How many of these could I have in my tank.

Many thanks

Rachel

 

[Carp4U]

I don't know through experience, but depending on the type of tetra you get, a shoal of tetras would probably nip the tail of the betta (presuming you like the colourful males). Maybe neon tetras would be okay but neons never do well in community tanks.
Mollies are fine, if you want them to breed then 1 male to at least 3 females if not I would just go for 3 females. After that you won't have much space so if you like tetras get a shoal of 5 cardinal tetras. After that, the tanks a bit full but you could maybe get away with a betta!

 

[Balloons&killies]

You could get shoal of 4-5 cardinals, and have 2 female bettas, females can be really colorful to just lacking the long fins,

 

[Wills]

It differs between what fish you want really, a good rule of thumb if your starting out is 1 inch per gallon but its not set in concrete by any means but it is a good way of working out figures for your tank ie if a betta is 2 inches allow 2 gallons for that but if a tetra is 1 inch allow 2 tetras per gallon for 2 reasons IMO one being they are smaller and less stocky than an inch of some other fish and also its important to keep shoaling numbers high so you have to balance your fishes requirements with your bio loads. So in a 60 liter tank from the fish you mentioned I would go for some of the torpedo shaped tetras as opposed to the disk shaped ones like neons, platinums, rummy nose etc and I would also advise not to go with mollies but platties as mollies grow quite large depending on their genetics and how they were raised as fry but still should grow quite large, where as platties are very similar but much smaller and available in just as many (if not more) colours. So for a 60 liter tank I would recommend a community of

1 Male Betta - your choice of colour and fin type all are same and just cosmetic choices down to you.
3 Male Platties - in a 60 liter tank you do not want to mix males and females as you dont have room for babies, 3 males will not fight but may squabble but not sufficiently to worry it just gives them character, I would suspect you get no damage to the fish but may notice some flaring etc which is not a bad thing - again you can choose the colours they can all be different as long as they are all male - I also say males as females could be pregnant or storing sperm in the store tank then give birth in your tank later.
6 Dawn Tetra - just my personal favorite tetra at the moment but like I say any torpedo shape tetra will work.

Wills

 

[BethK]

hi and welcome

well, i was say 3 male platies, 6 black neon tetra or cardinal, 6 female bettas or 1 male betta (don't put male and female bettas together).

there are many tail betta types with both male and female bettas, males having longer tails

 

[OldMan47]

Hi there Rachel.
There are lots of guides to how many fish you can have but most of them suffer from a common error. They do not take into account the simple factors of interspecies and intraspecies aggression and most of them also do not take into account the differences that result from the size and body shape of the fish. Another frequently missing bit of information is the water types preferred by each fish.
Betta splendens, the kind of betta you will find in most pet shops, are very adaptable in terms of their water but are often quite docile fish who become victims of any fast swimming or nippy fish in a tank. The mollies are best served by keeping them in small numbers in tanks filled with rather hard water with a pH over 7.5. Many but certainly not all tetras do best in relatively soft water with a neutral to low pH. I find that rasboras do fine in water that is just too hard for most tetras so I would substitute them in your mix if you have water suitable for mollies.
In a small tank like yours I would limit things to maybe 3 or 4 mollies, a half dozen tetras or rasboras and a single male betta. If you end up with the nippier tetras, leave out the betta. You don't to watch a betta just become a victim of other fish. Once you have a stocking similar to the one I have listed, wait a while to make sure your water is stable and you could add in some nice peppered cories, maybe 4 or 5 of them.

 

[RBurkett]

Hi there Rachel.
There are lots of guides to how many fish you can have but most of them suffer from a common error. They do not take into account the simple factors of interspecies and intraspecies aggression and most of them also do not take into account the differences that result from the size and body shape of the fish. Another frequently missing bit of information is the water types preferred by each fish.
Betta splendens, the kind of betta you will find in most pet shops, are very adaptable in terms of their water but are often quite docile fish who become victims of any fast swimming or nippy fish in a tank. The mollies are best served by keeping them in small numbers in tanks filled with rather hard water with a pH over 7.5. Many but certainly not all tetras do best in relatively soft water with a neutral to low pH. I find that rasboras do fine in water that is just too hard for most tetras so I would substitute them in your mix if you have water suitable for mollies.
In a small tank like yours I would limit things to maybe 3 or 4 mollies, a half dozen tetras or rasboras and a single male betta. If you end up with the nippier tetras, leave out the betta. You don't to watch a betta just become a victim of other fish. Once you have a stocking similar to the one I have listed, wait a while to make sure your water is stable and you could add in some nice peppered cories, maybe 4 or 5 of them.

 

[RBurkett]

Many thanks for your reply and your advice. I forgot to mention that at the moment I have 6 Molly {2 Sailfin males and 4 Females} 4 Silver tip tetras and 5 Neon tetras. The PH in my tank is normally 7.5 but all the fish seem to be doing ok. The Large Male Molly can be a bit feisty but I dont think he is aggressive {just possessive of the ladies}

I have recently added a piece of bogwood to my tank which I had soaked for a week and 2 tablespoons of aquarium salt upon advice from the Pet Centre. Is this ok?

Another query I have is how much water should I be changing each week, I have had so many different opinions. {which is very confusing}

Thanks for all your help

 

[BethK]

for a 60ltr, i always changed 50% every 5 days, seemed to work well.

 

[Curiosity101]

Sailfins in my opinion outgrow practically any 60l tank I can think of... They can easily grow 15cm which is massive in a tank that is probably 60cm in length.

If it were my tank then I'd definitely re-home the mollys in favour of a smaller livebearer such as platies (well actually that's a lie...I don't like livebearers that much lol). But other than that your tetras are a fine size and in an alright sized group.

As it stands I'd say the tank is fully stocked, if not slightly over stocked (possibly not overstocked 'yet' but only if the mollys aren't fully grown).

Salt isn't neccesary, your fish are freshwater not brackish and the pH is 7.5 implying it probably isn't too soft and definitely doesn't need to manually be hardened.

As for the weekly water change, that really depends on your water stats. I tend to do between 20-30% on my tanks but basically whatever keeps your nitrates at around 10-15ppm above your tap water value is a good guide.
What are you tank stats and tap water stats?

 

[OldMan47]

You have a fully stocked tank there Rachel. The salt is not needed but does serve a valuable purpose. It keeps your local pet shop in business by having you buy something. As both Curiosity and BethK have suggested, your stock level is high enough that frequent large water changes are probably needed. The guidance of using nitrates to judge how much water to change is good, I use a 20ppm change as my own guide. With your heavy stock levels you won't want to go much longer than a week between water changes. I would say there is no room in your tank to add a betta or any bottom dwellers.

 

[stubert]

If your wanting a betta, a good combo would be 1 betta and 6 or so corydoras, pretty much what i have plus a couple of bn plecs and a snail and its a good mix. bettas tend to chase top swimming fish (depending on the betta of course) but dont mind corys atall.

 

[RBurkett]

Thank you all for your comments, I forgot to mention the Mollies I have are only about 5cm in length. How long does it take for them to reach full size {which is 15cm I understand} Also how long does it take for the fry to reach 5 cm in length. I would like more fish, but from all your comments that doesnt look very advisable. {Even if my mollies are 5cm???}

My water details are:

Ammonia: 1.0 ppm
Nitrite: 0 ppm
Nitrate: 40 ppm
PH Balance 7.6

I did a 10L water change yesterday, do I need to do another one?

 

[Curiosity101]

Unless you re-home the mollies then I definitely cannot advise more fish. They will outgrow it...

And you ammonia level is actually really really high. That's easily high enough to cause permanent damage to the gills of your fish.
You need to get the levels down to below 0.25 max so two 50% changes would do it. But I would suggest one really large 80% change and then a 50% change as the level will increase again overnight and you presumably don't want the fish to suffer?

It's odd you're showing ammonia, has the tank only been put together recently? If you've had it for quite some time then an ammonia reading could be a couple reasons... either a) you changed your pads or b) your filter can't cope with the bioload of the fish or c)you've over fed/something is rotting in the tank.

 

[OldMan47]

You have deadly levels of ammonia at 1.0 ppm. You have an immediate need for a 75% or larger water change and increased monitoring so that you do not end up in that situation again. As others have already mentioned, it would be ill advised to add any fish to your tank until you can get things under control. I am sure the kids would love to watch the interesting fish go about their daily routines but I doubt they would enjoy watching their personal favorite fish suffer and die. I know that I will take extreme measures as a 62 year old adult to avoid needing to watch that myself. Instead, the large water change, with a lesson for the children about the need for a healthy environment to live in, will probably make them eager to see their favorite fish swimming in a better quality water. They will probably volunteer to help get it done if you approach it right.