My white lyre tail Molly died last night️

I don't know what happened. Had to scoop her out this morning and flush her
I've only had her a week.
Last night she was at the bottom of the tank, upside down and still breathing, but she kept snapping out of it and would swim again. Thought maybe she was playing dead, for that afternoon I had literally just added 3 new mollys, though maybe she was scared....? Could it have been the water from the pet store? Or was she scared to death?
My water checks out perfect.
All my other fish look healthy and happy.
It's a mystery.

 

Can you give us a little more information?

Tank size? Exact water parameters (GH, KH, pH, temp, ammonia, nitrites, nitrates)?

 

Sorry for your loss. If you give the water parameters then it would be very helpful.

 

Ok ph is around 6.5 ammonia is 0, and nitrate 0 temp 76 don't know the rest

55 gallons

20 fish all Molly platy and tetra besides 2 gourami and algae eater

 

What kind of algae eater and what kind of gourami? What how many mollies and how many of each sex?

 

I'm not sure what he is, I acquired him with a tank I purchased on Craigslist

Male powder blue dwarf gourami and male blue and red stripes dwarf gourami

She was Molly number 5, I had two males three females. 3 male platy 5 female platy.

 

I don't know why you guys introduces your fish in the main tank directly from the the pet shop. Before doing so please keep the fishes in a quarantine tank for a week. This may eliminates the chances of big loss. Some things have to be kept in mind if you have a community tank:

1.Quarantine your fishes before introducing to the main tank.
2.Always introduce the aggressive fishes at the end. May be the Mollies are not so aggressive as your gourami. So please make sure you have introduced the less aggressive species first and the aggressive one in the last.
3.Never put the fish along with the water brought from the pet shop tank.
4.Do a basic research before buying any fish for you community tank. Because in community tank all the fishes have to share the common environment. So it is difficult for everyone to get acclimatized.

 

Now another one of my female mollys are acting strange, like the one that died. Swimming erratically up and down the sides of the tank. She really seems like she's going crazy. Can I upload video of her somehow? I've also noticed a couple of my fish twitching or something. This is all very sudden. Anyone have a guess?

The male is chasing her and mating with her relentlessly I noticed

 

I'm not sure what he is, I acquired him with a tank I purchased on Craigslist
Male powder blue dwarf gourami and male blue and red stripes dwarf gourami

She was Molly number 5, I had two males three females. 3 male platy 5 female platy.

Rehome one of the male gouramis before you come home to a beaten up or dead fish.

I'd rehome the females - the females aren't in large enough numbers to keep male harassment under control, and adding more females will mean that you'll get more fry and be overrun with fry faster.

I don't know why you guys introduces your fish in the main tank directly from the the pet shop. Before doing so please keep the fishes in a quarantine tank for a week. This may eliminates the chances of big loss. Some things have to be kept in mind if you have a community tank:

1.Quarantine your fishes before introducing to the main tank.
2.Always introduce the aggressive fishes at the end. May be the Mollies are not so aggressive as your gourami. So please make sure you have introduced the less aggressive species first and the aggressive one in the last.
3.Never put the fish along with the water brought from the pet shop tank.
4.Do a basic research before buying any fish for you community tank. Because in community tank all the fishes have to share the common environment. So it is difficult for everyone to get acclimatized.

A lot of us do quarantine. If you are going to quarantine, 3-4 weeks is a good time. One week isn't long enough - diseases/issues could easily show up after one week. I had hatchetfish develop ich during week 2 of quarantine.

Agreed that new fish could be passing around diseases though.

Now another one of my female mollys are acting strange, like the one that died. Swimming erratically up and down the sides of the tank. She really seems like she's going crazy. Can I upload video of her somehow? I've also noticed a couple of my fish twitching or something. This is all very sudden. Anyone have a guess?

The male is chasing her and mating with her relentlessly I noticed

Your pH is too low for mollies and platies. I'd guess you have a low KH and GH too. Mollies and platies need hard water, and this may be the issue (or related to it). I'd add a bag of crushed coral to the filter to raise the GH, KH, and pH.

Knowing the nitrites would help too.

If you have 0 nitrates, your tank isn't cycled.

 

Rehome one of the male gouramis before you come home to a beaten up or dead fish.

I'd rehome the females - the females aren't in large enough numbers to keep male harassment under control, and adding more females will mean that you'll get more fry and be overrun with fry faster.



A lot of us do quarantine. If you are going to quarantine, 3-4 weeks is a good time. One week isn't long enough - diseases/issues could easily show up after one week. I had hatchetfish develop ich during week 2 of quarantine.

Agreed that new fish could be passing around diseases though.



Your pH is too low for mollies and platies. I'd guess you have a low KH and GH too. Mollies and platies need hard water, and this may be the issue (or related to it). I'd add a bag of crushed coral to the filter to raise the GH, KH, and pH.

Knowing the nitrites would help too.

If you have 0 nitrates, your tank isn't cycled.

That is true, the 1 week for quarantine is too short, but I believe in something is better than nothing.