4ft Tank Stocking

I was wondering how many fish i could keep in my 120cmx50cmx50cm tank and i want to see if this is a reasonable amount:
40 platys
25 corydoras
5 mollies
20 swordtails

I will have a filter that does 900 l/h minimum and it will be planted.

Would this be overstocking? and if so how many of each are possible?

Way too many fish.

Don't keep swordtails and platies together because they hybridise. Either keep one species or the other, but not both in the same tank.

If you have female swordtails, platies or mollies, you will get babies.

Corydoras catfish naturally occur in soft water (GH below 150ppm) and a pH below 7.0.

Common livebearers like swordtails, platies, mollies and guppies do best in water with a GH above 200ppm (250ppm+ for mollies) and a pH above 7.0.

I would keep 10 platies & 5 mollies, or swordtails or mollies (not 10 of each), and 10-15 Corydoras. A total of about 25 fish.

Ideally we would want to know your GH; which can be obtained through your water companies website. I completely agree with Colin here, a bit too many fish in a 4ft, plus the plants would decrease the amount of swimming room so you would really only have about 3ft depending on where you are placing the plants.

Edit: It's not way too many but still a bit overstocked imo.

ok so if i were to be going the platy and molly fish, ,my water GH is 260 ppm and and my pH is 7.5, and lets say i have 30 platies, 5 mollies and lets say 15 corydoras, i intend on pulling the babys out and growing them out, just because it might be able to pay for itself then or even just get a lil bit off cost. i plan on doing it like Iwagumi Style which is quite minimal with a carpet... is this more reasonable?

Fish4dawin said:

Ideally we would want to know your GH; which can be obtained through your water companies website. I completely agree with Colin here, a bit too many fish in a 4ft, plus the plants would decrease the amount of swimming room so you would really only have about 3ft depending on where you are placing the plants.

Edit: It's not way too many but still a bit overstocked imo.

Click to expand...

Unless you have another tank/ pond for the babies, there are still too many fish. 30 platies is a lot of fish and each female can drop between 10-100 babies every month.

The GH is great for livebearers but a bit high for the Corydoras who naturally occur in softer water (GH below 150ppm).

On the Corydoras fish, they need dim light and from the indication here (iwagumi) this is not the case. Floating plants are frankly necessary with cories. They feel vulnerable when exposed under tank lighting, and bright lighting given the intended style. Here are photos of two upper Rio Negro habitats to illustrate. Marginal terrestrial vegetation and forest cover provide the shade that in the aquarium would be floating plant cover.