Weird Molly Behaviour

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technosguy

Aquarium Advice Apprentice
Joined
Oct 10, 2019
Messages
22
Hello folks.

I have a female ballon molly, she is behaving weirdly last couple of days, her fins are closing in, her tail looks like she has shrunk it, in the past it looked more like a fan. She stays in one spot most of the time balancing herself with side fins, she eats normally, however if she wanna move from a spot to another she wiggles her body, she rarely uses her fins in full action.

I think she is sick, but I got no idea what disease it may be.


Water quality is ok. I did a hundred percent water change today, water parameters are ok right now. But before I do water change, water was very cloudy due to a bacterial blooms and I believe my ammonia was high because of that bacterial bloom. My tank supposed to be cycled, but since I added my 20 juvenile guppies and it started to get cloudy.

I have 2 sailfin mollies , 2 ballon mollies, 2 pearl gouramies, a female guppy, 20 juvenile guppies (4 weeks old)

It’s 162 litres aquarium. Over the top built in filter, a deep gravel bed as substrate and three fake plastic plants.
 
I attached some photos of the fish
 

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the cloudiness sounds like a bacterial bloom. A small water change every couple of days should clear it up. What is the temperature of your aquarium? What are your exact water parameters? Adding the guppies all at once may have added some ammonia.
 
Hello tech...

Abnormal fish behavior is caused by a sudden change in the water chemistry. A change, no matter how small, will affect a sensitive fish like a Molly. They're the most sensitive of all the livebearing fish to changes in their water. I never change less than half the water in my fish tanks and I do it weekly. Changes less than half, leave too much of the old, polluted water in the tank. The fish will add to that before the next water change. Even if there's no trace of ammonia or nitrite in the water, the nitrate can affect a Molly. Work up to the point you change half the water weekly. For Mollies, larger water changes are really needed.

B
 
the cloudiness sounds like a bacterial bloom. A small water change every couple of days should clear it up. What is the temperature of your aquarium? What are your exact water parameters? Adding the guppies all at once may have added some ammonia.


My water has been cloudy for a week, I googled it, they said patience is the best for a bacterial bloom, I was sure it’s bacterial bloom also. But today is the 7th day and I had to do something after I saw my molly shrinking her fins, so I did full water change. My water temperature goes between 24 up to 28 Celsius.

I never expected a tiny 20 juveniles 4 weeks old guppies would have such great effects on my aquarium.

Water TDS is 200, pH is between 7.5 to 7.9, nitrite and ammonia now are undetectable. But it was high before I change the water. Also water is free of chlorine, Total chlorine test gives me zero.
 
Hello tech...

Abnormal fish behavior is caused by a sudden change in the water chemistry. A change, no matter how small, will affect a sensitive fish like a Molly. They're the most sensitive of all the livebearing fish to changes in their water. I never change less than half the water in my fish tanks and I do it weekly. Changes less than half, leave too much of the old, polluted water in the tank. The fish will add to that before the next water change. Even if there's no trace of ammonia or nitrite in the water, the nitrate can affect a Molly. Work up to the point you change half the water weekly. For Mollies, larger water changes are really needed.

B

I thought mollies are hardy to be honest. I remember reading something which said they are hardy, it was an article I found on google. I like to read, so when I get bored I google fish names to get more information about it.
 
Hello again...

If you're into fish keeping, you can't be too well informed. I've read a number of books on tank keeping. The best is "A Simple Guide to Freshwater Aquariums" by David E Boruchwitz. He's been keeping fish since the 1960s and I don't think you can find anyone more knowledgeable.

B
 
I’ll try to read that book, thank you very much. Also it’s very appreciated if you share the other book’s titles that you read.
 
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