Molly acting weird

[Cwehling]

Hi, I’m relatively new with my aquarium. It’s been three weeks and I have a tank of Molly’s. Two dalmatians, two sail fins, and two balloons.
Three days ago, one of my sail fin was acting like she couldn’t swim, like she kept sinking. She did not eat that day and the next morning she was dead. I have a 37 gallon tank and all the fish are two weeks. They are all pretty young I assume because no one is 2 inches long yet. They all get along and came from the same aquarium store. My water is testing good., according to the master kit. my filter is for a 70 gallon and I did a 25% water change five days ago. I also have a bristle nose Pleco, so I can’t put aquarium salt in the water. Today, one of my balloon fish keeps trying to bounce off of one of the ornaments. it almost looks like he wants to scratch or some thing. None of the fish have spots, so I don’t know what’s going on. Is there some thing I’m missing? I called the aquarium store and I’m going to pick up API parasite general purpose just in case they have something internal. Otherwise I’m not sure what to do, or if this is just a weird fish. I don’t want anyone else dying. Thank you so much.

 

[Colin_T]

Hi and welcome to the forum

Don't add anything to the tank unless you know what the problem is. Adding chemicals/ medications to a tank that might have a water quality issue or some other issue will simply make the problem worse.

Don't add any more fish until the tank has settled down and don't add new fish for at least one month after a fish dies. Adding more fish can introduce new diseases and put more stress on the original inhabitants, making things much worse.

Post pictures of the fish and a picture of the entire tank.

What is the ammonia, nitrite and nitrate of the aquarium water and tap water (in numbers)?

How often are you feeding the fish?

How often do you do water changes and how much do you change?
Do you gravel clean the substrate when you do a water change?
Do you dechlorinate the new water before adding it to the tank?

What sort of filter is on the tank?
How often and how do you clean the filter?

What are the tank dimensions (length x width x height)?

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What is the GH (general hardness), KH (carbonate hardness) and pH of your water supply?
This information can usually be obtained from your water supply company's website or by telephoning them. If they can't help you, take a glass full of tap water to the local pet shop and get them to test it for you. Write the results down (in numbers) when they do the tests. And ask them what the results are in (eg: ppm, dGH, or something else).

Depending on what the GH of your water is, will determine what fish you should keep.

Angelfish, discus, most tetras, most barbs, Bettas, gouramis, rasbora, Corydoras and small species of suckermouth catfish all occur in soft water (GH below 150ppm) and a pH below 7.0.

Livebearers (guppies, platies, swordtails, mollies), rainbowfish and goldfish occur in medium hard water with a GH around 200-250ppm and a pH above 7.0.

If you have very hard water (GH above 300ppm) then look at African Rift Lake cichlids, or use distilled or reverse osmosis water to reduce the GH and keep fishes from softer water.

 

[Colin_T]

BASIC FIRST AID FOR FISH

Test the water for ammonia, nitrite, nitrate and pH.

Wipe the inside of the glass down with a clean fish sponge. This removes the biofilm on the glass and the biofilm will contain lots of harmful bacteria, fungus, protozoans and various other microscopic life forms.

Do a 75% water change and gravel clean the substrate every day for a week or until the problem is identified. The water changes and gravel cleaning will reduce the number of disease organisms in the water and provide a cleaner environment for the fish to recover in. It also removes a lot of the gunk and this means any medication can work on treating the fish instead of being wasted killing the pathogens in the gunk.
Make sure any new water is free of chlorine/ chloramine before it is added to the tank.

Clean the filter if it hasn't been done in the last 2 weeks. However, if the filter is less than 6 weeks old, do not clean it. Wash the filter materials/ media in a bucket of tank water and re-use the media. Tip the bucket of dirty water on the garden/ lawn. Cleaning the filter means less gunk and cleaner water with fewer pathogens so any medication (if needed) will work more effectively on the fish.

Increase surface turbulence/ aeration to maximise the dissolved oxygen in the water.