Dying and Stressed Fish! Help!

[catfishkid]

Yesterday evening I checked up on my tank and found one of my zebra danios dead! I haven't had the best luck with these fish but this one's lived for a few months. So what could have been the cause of death for him?

Then today I found my favorite fish dead too. My dalmatian molly. But he wasn't like the danio, his top fins were absolutely shredded.

So now my other molly (pregnant with her 2nd batch of fry) is crazy stressed out. She ate when I fed them, which is an okay sign to me, but I had to put her back in the breeder box and she calmed down a bit.

The other fish in my tank are: 2 zebra danios, 2 Julii corydoras, 1 pregnant dalmatian molly, 6 molly fry, and snails. Which one of them is likely to be the bully? My dad suspects the female molly but do females attack their breeding partner?

 

[Hunnelips]

I've had many mollies throughout the years and have learned one thing. They do best with platys and swordtails as they are the only fish that put up with the salt requirement mollies have. Believe it or not the zebra danios are the biggest bullies in your tank. I doubt however they are bothering the mollies.

Make sure you have one teaspoon of aquarium salt per five gallons water. Mollies are truly a brackish fish. Without the salt they don't last longer than a year.

If the salinity in your tank is fine then I would check other parameters such as ammonia, nitrite and ph.

 

[Canary bird]

I've had many mollies throughout the years and have learned one thing. They do best with platys and swordtails as they are the only fish that put up with the salt requirement mollies have. Believe it or not the zebra danios are the biggest bullies in your tank. I doubt however they are bothering the mollies.

Make sure you have one teaspoon of aquarium salt per five gallons water. Mollies are truly a brackish fish. Without the salt they don't last longer than a year.

If the salinity in your tank is fine then I would check other parameters such as ammonia, nitrite and ph.

Good advice, but I have had the same 4 mollies for well over a year in freshwater no salt at all and they are all good , infact they won't stop breeding now lol

 

[BBradbury]

Hello cat...

Most, if not all tank problems are caused by less than perfect water conditions. If you don't remove and replace half the tank water weekly, your fish and plants won't be has healthy as they could. Large, frequent water changes keep the water chemistry stable, because they remove most of the toxins and the rest are diluted to the point they don't present a problem for your fish.

Get some floating plants into the tank. Anacharis (Brazilian water weed) is one of the best natural water filters and will use what little nitrogen is left from the water change.

A little standard aquarium salt is important to "Livebearing" fish, especially Mollies. I use a teaspoon in every 5 gallons of replacement water. I keep a large number of different species of Corydoras and they do fine with a little too.

Change a lot of the tank water, change it frequently and plant your tank. The fish will take care of themselves.

B

 

[Hunnelips]

Good advice, but I have had the same 4 mollies for well over a year in freshwater no salt at all and they are all good , infact they won't stop breeding now lol

I guess there is always exceptions to everything...the mollies available in my area get pretty sick without brackish water.

 

[Fishlover3578]

I had a guppy female kill an endler guppy male half her size when I had to temporarily overstock a 10 gal due to power out in part of house with 29 gal