Mollies and Corydoras

[Jor124dan]

I have a 40 gal bow front tank that is 30 in by 15 in by 24 in tall. I currently have a aquaclear 70 hob filter. water parameters are all good and tank is cycled. I wanna get mollies and corydoras. My question is how many I can do I wanna start with 4 female mollies and 2 male mollies. I kind of struggling on how many corydoras to put in the tank. I wanna have some room to keep some baby mollies in the future. I was thinking around 2 corydoras but know they need to be in groups. I just don't want to get to many fish in my tank and want the mollies as the showcase of the tank. I just want to have a small clean up crew on the bottom of my tank.

 

[Jor124dan]

I have a 40 gal bow front tank that is 30 in by 15 in by 24 in tall. I currently have a aquaclear 70 hob filter. water parameters are all good and tank is cycled. I wanna get mollies and corydoras. My question is how many I can do I wanna start with 4 female mollies and 2 male mollies. I kind of struggling on how many corydoras to put in the tank. I wanna have some room to keep some baby mollies in the future. I was thinking around 2 corydoras but know they need to be in groups. I just don't want to get to many fish in my tank and want the mollies as the showcase of the tank. I just want to have a small clean up crew on the bottom of my tank.

 

[Colin_T]

Mollies and Corydoras come from different water.
Mollies need a GH above 250ppm and a pH above 7.0.
Corydoras come from water with a GH below 150ppm and a pH below 7.0.

Mixing the 2 types of fish in the same tank means one species is going to suffer from incorrect water chemistry.

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If you want to keep livebearers like mollies, keep them in single sex tanks (all males or all females). This stops the males harassing the females.

 

[Freddo96]

Mollies and Corydoras come from different water.
Mollies need a GH above 250ppm and a pH above 7.0.
Corydoras come from water with a GH below 150ppm and a pH below 7.0.

Mixing the 2 types of fish in the same tank means one species is going to suffer from incorrect water chemistry.

-------------------
If you want to keep livebearers like mollies, keep them in single sex tanks (all males or all females). This stops the males harassing the females.

I have seen mollies be acclimated to salt water its just the way you go about it they thrive in many different conditions however I do agree with the all males or females

 

[CassCats]

There are some cories who can be in the same water as mollies, as long as the GH does not go above 260ppm

Problem will be is if your GH is BELOW 250ppm, because then water is too soft for mollies. They will NOT thrive in soft water.

Look up your GH. Either test for it with the API tests or look on your water providers site.

Let us know the GH and we can advise you further.


And corydoras for harder water, see here:

Corydoras for Hard Water List

In general, it's easy to say that most bottom dwellers are from softwater habitats, but there are a few exceptions if one does enough digging around. This is a list of corydoras suitable for ranges 200ppm and up, but be aware it may vary availability for your particular water as some are...

www.fishforums.net

Look at the ones suitable for up to 268ppm and choose one of those. Any of the others won't thrive in water higher than their range.


Cories need a minimum of 6 to feel secure. More is even better. Your tank is technically 46 gallons (I have the same bowfront). You could comfortably fit 15 cories no problem. Maybe more, but mollies have a very high bioload so keeping the number a little lower than id suggest normally to account for that.

 

[Naughts]

Cories should be kept if we like them, not if we want a "clean up crew". They have their own needs (a shoal of 6+, omnivorous sinking pellets/ wafers, sand substrate, softer water etc.) and it is our responsibility to make sure these needs are met.
If there is excess food it is because we have overfed the fish. Rather than get fish that only serve to clean up, it is better to keep the tank clean by feeding appropriate amounts and regular maintenance.

 

[CassCats]

If clean up crew is what you want, hands down suggest a big group of ghost shrimp. They don't breed easy like cherry shrimp though, so buy the big group. You could fit many. They're fantastic cleaners for scraps of food missed in small places, or just fun to watch actually.

 

[Colin_T]

I have seen mollies be acclimated to salt water its just the way you go about it they thrive in many different conditions however I do agree with the all males or females

Mollies are fine in hard water, brackish water and sea water, but they don't tolerate soft or acid water. As long as the GH is above 250ppm and the pH is above 7.0, they will be fine.