Betta With Mollies & Platies In 20g Long


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2 years
Hello fishlore, it has been a while since I have logged on so let me give you an update. The 29 gallon is gone due to a massive leak, and has been replaced with a 20 gallon long.

2og long
2x silver lyretail mollie (1 male, 1 female)
2x gold panda mollie (both male)
2x twin sidebar platy (1 male, 1 female)
2x mickey mouse platy (both females)
1x red wag platy (female)

Blue veiltail betta

Now, I would like to get rid of a minor fry problem in the 20 gallon long. I have only seen 2 fry, but I know that can change fast. I can get rid of a few fry, but in massive numbers fry become difficult to find what to do with. I know my betta would enjoy feeding on the fry. I am not worried about him getting along with the platies, as they have no long fins. 1 of the lyretails is my concern. I have seen him nip at other mollies occasionally, but only if they bump into each other while feeding. I have 2 fish caves and 8 plants for them to hide in and around, and I know the betta cannot catch them.

I want to move the betta from the 10 gallon for 2 reasons

1.) fry control
2.) the 10 gallon is unheated, but I am in texas in the middle of summer with the tank next to the window and the temperature is maintained at 72 degrees even at night, so I am not to conerned.

I can also move the only male platy into the 10 gallon by himself to help keep them from breeding.

would you recommend doing this?

Small Tanks

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This is NOT a good plan.

The betta will get aggressive with the mollies and platies and everyone's going to get stressed.

Instead, net your fry and toss them into the betta tank with him.

Also your betta DOES need a heater he should be kept at 75F minimum, closer to 80F is better.


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If the betta were a female this could work. But telling you right now, from experience, platys will bite the long fins on a male betta, and the betta will be super stressed, constantly flaring and chasing, never getting any rest. Also, bettas need temps above 75, 78-80 is ideal.

I strongly suggest you get your betta a heater. 72 is too cold for him. Is he lazy? If yes, its because he's too cold. Putting him by a (closed) window does nothing for the temp, all it does is feed sunlight to algae.

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