My Mollies Keep Dying... Please Help :/

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kadkins20

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I recently set up my 55-gallon tank, i used some gravel from my brother's existing tank to cycle the tank and 2 or 3 days later i bought 12 fish from Petsmart: 2 cory catfish, a pictus catfish, a pleco, 4 platies, and 4 mollies. That night, 2 of my mollies died, and within 3 days the other two died as well. I have replaced them since then, and 2 of them died within one day, the other one held on for 3 days and finally died. One of them is doing well. All of the other fish are happy healthy, active, and eating. I have tried different colored - and finned - mollies and they have all died except for one silver lyretail molly.

I have a powerfilter rated for a 75 gallon tank and a heater that keeps the tank at 76 degrees (Fahrenheit)

They showed no signs of disease, and most of them were active and vibrant right until they died. I have been feeding them tropical flakes and sinking bottomfeeder wafers for the catfish. The mollies have not been overeating before they died (most of them didnt eat the first day anyway, before they died).

Please give me any solutions you can think of for keeping my mollies alive. The label at petsmart says they are supposed to be easy to take care of, although my brother has told me not to get them because they die, i really like the way they look and want to be able to keep them. Any advice would help, including "go somewhere else for mollies."

I have a freshwater test kit and will be testing my water later today

thanks for your help :p

Ken
 
Hi Ken
well firstly i must say that there is actually little bacteria in the gravel, it would have been much better to have added some mature media from your brothers filter,
with just this small amount of bacteria going into the tank i'd say that the tank couldn't have become fully cycled.
did you test the water before adding the fish? It may have been simply due to very different water parameters,

Is it just the mollies that are dying?
Do you know if your LFS puts salt in with their mollies?, if they do then this could be another explanation

Lastly what size tank do you have?
 
actually, i just got back form my brother house and one of my platies is dead :/ but the platies have been alive for a little over a week now and the mollies have been dying within a day or two

i have had 7 mollies die, and only one platy

i do not know if they use aquarium salt in the molly tanks at petsmart :/ ill check that

my tank is 55 gallons, so thats about 210 liters (a little less)
 
Ok i'd say that the deaths are either caused by the mollies being transferred from brackish to freshwater and not being able to adjust Or more likely IMO the tank isn't cycled and the mollies are feeling it the worst.

Once water tests are done we will have a better idea
 
You're right! Got some ammonia a little over 1.0, and nitrites and nitrates are reading at 0. Ph is a little high, shouldn't be too high for mollies but if they have been housed at a lower ph the change may be too much for them. Going to do a water change and I will check with petsmart to see if they are using salt.

If I do add salt will that be a problem for any of my other fish?
 
My LFS uses aquarium salt and I got some. I haven't added it yet, how much should I add?

I have some small plants in the tank, that shouldn't be a problem though.
 
Don't add salt. Even if the LFS keeps them in salt water the transition couldn't be that traumatic. It'll just been to many fish for the bacteria to handle. You have to wait until it grows before adding loads of fish. I wouldn't add anymore than six after a month of fishless cycling. Then wait another month before adding any other fish. Mollies are great fish and I love mine which are kept in freshwater.
 
ive been reading through the forums, and it sounds like mollies really do significantly better with aquarium salt, and since they keep them with some salt at my LFS, is it possible that this could be why they are dying? Now, i keep fish other than mollies in my tank, so i was wondering if it would be a good or bad idea to add salt, or if there were some kind of happy medium i could find to, say, only make the water a bit more salty. Or if maybe i should jsut forget about keeping mollies with my other fish.
 
ive been reading through the forums, and it sounds like mollies really do significantly better with aquarium salt, and since they keep them with some salt at my LFS, is it possible that this could be why they are dying? Now, i keep fish other than mollies in my tank, so i was wondering if it would be a good or bad idea to add salt, or if there were some kind of happy medium i could find to, say, only make the water a bit more salty. Or if maybe i should jsut forget about keeping mollies with my other fish.

They do better with marine salt (different than aquarium salt, which won't serve long term for the same purpose), shock could be doing it, but the ammonia levels you mentioned are toxic to just about any fish, and shock from salinity changes should be killing faster than a day or two. Mollies are very adaptable to salinities. As for the pH - they like it high, and brackish water tends to have a very high pH anyway.

I've heard a good few people have their first fish last for weeks with high ammonia, but new fish croak within hours from the sudden exposure to ammonia - if the levels aren't fixed, the first fish will usually die as well.

Fresh water fish vary a lot in how they handle salt, but in general, if they don't need it, don't use it. The happy medium would probably be hard alkaline water, not an extra light brackish.

For immediate terms, address ammonia and (eventually) nitrite levels - neither should be allowed over .25 at any time. If you try to raise the salinity now, you'd just go broke adding it with all the water changes while ammonia and nitrite are still present.
 
I havent kept tropical for years, only my bettas. I got 5 mollies about a week ago and put them in a set up tank and they immediately looked sluggiosh. I dissolved a tiny amount of aqua salt in warm water and within seconds they perked up! My next door neighbour has mollies die on her all the while, so I have given her this tip as well. All y bettas have the merest hint of salt in their water as well. and they really thrive.
 
im getting a lot of mixed responses, i dont really know what to do... is there anywhere where i could get more definitive answers?

is adding salt going to hurt my pleco or cory catfish?

and should i add the amount the salt container says? or more? or less?

sorry for all the questions :p but my brother insists that aquarium salt would be extremely bad for my catfish, and also reminds me all the time that he had mollies using my water and htey lived for a long time and had lots of babies, and then here on the forums i have people telling me to add aquarium salt and people telling me not to, and its really jsut confusing me :/
 
Seeing as you are recording a level of ammonia in the tank that should be your first priority
I would do a 30% water change today and then test the water again, you will need to do this daily until the nitrite and ammonia have both settled at 0

Once the parameters have been stable for a few days you will be able to see how the fish are behaving in the ideal conditions meant for them
IMO if they are doing fine in your brothers tank then hopefully they will be fine in yours

To clarify i will say that in most cases mollies do prefer a little salt, however as your brothers stated any South American Catfish will not handle salt well/
 
Yes the salt is NOT good for the cories so please dont add any all the time they are in there.

Best bet is to take all the fish back and complete a fishless cycle.

Within that time study fish which are compatible with each other.

Good luck :good:
 

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