Molly died - help identify problem?

[Patti7dc]

So I have an established tank where I take parameter readings 2-3 times a week. The ammonia and nitrite always read at 0ppm (unless I have just added a fish) and the nitrite gets to 20 before I do a 30% water change. I recently noticed that my gold dust molly started to look thinner. I made sure she was getting food at feeding time (I have a group of female bettas in the community tank that are big pigs at eating time) and she seemed to be eating fine and getting along well with all the other fish. Instead of the normal looking stomach it started to look like it was becoming concave. This was probably went on for a week or two. Then one day I looked in the tank and she was laying on the bottom, like she was taking a nap. She would swim around if I walked up to the tank but otherwise she was just laying around not doing anything. I knew this was a bad sign and within the next two days she had become unable to swim straight, was spinning around when she tried to move, layed on the bottom, gasped a bit, and then stopped moving alltogether and died. Now I'm really bummed! She was such a pretty fish and I really liked her and I don't know what happened. When I saw her acting strangely I checked the parameters. Ammonia was between 0 and 5ppm (color was between the two) and I figured that was normal since I had just added a new fish. Nitrite was 0ppm and Nitrate was less that 5ppm. So the water was great. I keep a little bit of salt in the aquarium, every couple water changes I slowly add in one tablespoon per 5 gallons. It's not a lot but it helps a little with the ions. So I have no idea what was wrong with her but I don't want to buy more fish if they are going to die. I've had her for over a month and she seemed fine until she started looking thin. Any ideas?? Thanks in advance and sorry if this is long!

 

[OrangeCones]

Sorry for the loss of your fish.

So I have an established tank where I take parameter readings 2-3 times a week. The ammonia and nitrite always read at 0ppm (unless I have just added a fish) and the nitrite gets to 20 before I do a 30% water change.

It is not normal to show a reading above zero for ammonia or nitrite after adding a fish. It is an indication that the bioload is overtaxed. I am assuming that you mean NITRATE gets over 20 here...

Ammonia was between 0 and 5ppm (color was between the two) and I figured that was normal since I had just added a new fish. Nitrite was 0ppm and Nitrate was less that 5ppm. So the water was great.

No amount of ammonia above zero is 'great.'

I've not seen the first measurement above zero to be 5ppm. 5ppm ammonia would be lethal very quickly. My test kit meassures ammonia as

0
0.25
0.5
1
2
4
8

What test kit are you using?

 

[FreshyFresh]

This does seem odd given the facts/figures listed in your signature. That's not a lot of fish for a 55gal tank. What type of filtration do you run in this tank?

 

[Patti7dc]

Mis-typed sorry

Sorry for the loss of your fish.



It is not normal to show a reading above zero for ammonia or nitrite after adding a fish. It is an indication that the bioload is overtaxed. I am assuming that you mean NITRATE gets over 20 here...



No amount of ammonia above zero is 'great.'

I've not seen the first measurement above zero to be 5ppm. 5ppm ammonia would be lethal very quickly. My test kit meassures ammonia as

0
0.25
0.5
1
2
4
8

What test kit are you using?

Yes - sorry I meant nitrAte will get to 15-20ppm and then I will do the water change.
And you are right about the ammonia reading - sorry again. The reading is between 0 and 0.25ppm - and I was told that when you add a new fish it can show above 0 while the bio-filter is adjusting to the new addition. (Which is why I only add one or two fish at a time)
I use the API freshwater testing kit.

 

[Patti7dc]

FreshyFresh - I use a penguin filter that I got from my friend with the 55 gallon tank and stand. It has the physical filters with charcoal that I change and it also has bio-media in one side and a bio-wheel in the other side. And I definitely kept it in mind not to over-stock my tank. All the fish are pretty small right now but they all get along great and there is a great balance of top, bottom, and mid swimming fish. I definitely felt like something was wrong with her when she started looking so skinny since Molly bellies are usually so round.... but I have no idea what would have happened to her that wouldn't have affected any other fish. :-(

 

[FreshyFresh]

Patti, how did you initially set this tank up, fishless cycle or fish-in cycle? How long has it been setup?

With that light of a stocking and a proper nitrogen cycle going on, I'd think you should never see any ammonia in the tank.

 

[Patti7dc]

I set up the tank 3 months ago, fishless cycle. Stocked it and got ick from some lfs, lost 5 fish before it cleared up. I treated it with heat and aquarium salt and most of the fish survived.

I figured a tiny reading of ammonia would be okay with the addition of a new fish. The ammonia and nitrites are always reading at 0ppm. But even that tiny amount of ammonia (0.25ppm) wouldn't affect one fish that way, would it?

 

[FreshyFresh]

Nice! Sounds like you did your homework.

Main thing is you monitor for ammonia/nitrites/nitrates and know what to do when you get them.

I hear you on getting ick right off the bat . I'm battling it right now in my 29G.

 

[FishDad]

If all are normal with the other fish it may have just been an isolated incident. Your ammonia going up and down is very suspect though. I would inspect your filter and make sure all is kosher there.

 

[OrangeCones]

It has the physical filters with charcoal that I change

Patti - if you are regularly changing your filter media, you may be throwing your tank into a mini-cycle repeatedly. The filter media contains a lot of beneficial bacteria.