Fish Dying ?

[cat636]

Hi everyone!

I was hoping to get some help. So, I got a freshwater tank in Setember last year. I follow all the tips i could find so it would go smootly.
I have 7 corys in the tank and 3 plecos (i know you not supposed to keep plecos together, i didnt know about that until recently but they have been together for months now and everything is fine).
Now my problem is, even thougth all these fish are doing great, any other fish i try to put in the aquarium dies. Mollys, Guppys, Kuhlis, everything i have had besides the corys and the pelcos have died. Recently i got 4 mollys and now i only have one.
Am i doing something wrong? Could it be a disease that i didnt see? I just find it weird that all the other ones die and these are still alive and have been for months.

Can anyone help me out?

Thank you!

 

[Sgooosh]

Hi everyone!

I was hoping to get some help. So, I got a freshwater tank in Setember last year. I follow all the tips i could find so it would go smootly.
I have 7 corys in the tank and 3 plecos (i know you not supposed to keep plecos together, i didnt know about that until recently but they have been together for months now and everything is fine).
Now my problem is, even thougth all these fish are doing great, any other fish i try to put in the aquarium dies. Mollys, Guppys, Kuhlis, everything i have had besides the corys and the pelcos have died. Recently i got 4 mollys and now i only have one.
Am i doing something wrong? Could it be a disease that i didnt see? I just find it weird that all the other ones die and these are still alive and have been for months.

Can anyone help me out?

Thank you!

how big is the tank
type of cory
type of pleco
is the tank cyclied
water parameters?

 

[PlasticGalaxy]

The keeping plecs together thing isn't inherently true, depends on the species you have. Under the assumption that they're common plecs, they are generally fine when they are very young and small, but will become territorial as they get bigger.

First thing's first, your water parameters. Do you know what your nitrite, nitrate and ammonia levels are? The first thing people assume when fish are dying or otherwise stressed is that it could be due to a spike in the ammonia.
Ammonia spikes can be caused by a multitude of things:

• Adding a large amount of fish at once and/or adding water from fish bags.
• Overfeeding - in which case the fish won't eat it all and then leave it to rot.
• Lack of substantial water changes in conjunction with lots of fish excrement (which would be down to the 3 plecs).
• Clogged or unclean filter.

I would suggest doing a quick test of your water parameters, then a large water change to reduce ammonia that may come from the bodies of the dead fish. If the filter hasn't been cleaned for a while, wring out the sponges into tank water and make sure nothing's clogging it.

Another thing that might be helpful: noting additional water parameters such as water hardness, pH and average temperature.

 

[TwoTankAmin]

There can be any number of reasons for what you are experiencing. Fish keeping often involves a lot of detective type work. We have to figure things out based on the "clues."

The fact that you had a successful tank going would suggest the problem is not something nasty lurking in your water. So the next question I would want to know the answer to is from where did you acquire the new fish? If they all came from the same source that would suggest the problem is there.

Corys and plecos tend to prefer softer water. But depending on the specific species they may prefer warmer or cooler water.

Mollies and guppies would prefer water a bit harder. Mollies often need some salt in the water but your other fish would not like this at all. But gups are fairly hardy and should not have big issues with water that cories and plecos like.

Kuhlis like to dig into the substrate. The should be kept in a tank with a sand bottom:

Care: All kuhlis need well-established aquaria and should not be considered for newly set up tanks. Lots of hiding places with soft substrate. Best kept in groups, the larger the better. Three fish is the absolute minimum that should be kept together.

from https://www.loaches.com/species-index/pangio-kuhlii

As asked above post as much info as you can about the tank-
size, contents (deocor, substrate and equipment), water parameters (pH, GH and temp. especially), what test kits do you have,
where do you get your fish and how do you intriduce them into your tank?

 

[Colin_T]

Any pictures of the sick fish?

The GH (general hardness), KH (carbonate hardness) and pH of your water supply 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).

------------------
Find out when the shop gets fish in and then wait a week before getting any.

Don't buy fish on the day the shop does water changes, and don't buy fish for at least 3 or 4 days (preferably a week) after the shop does water changes. The fish stress after a water change and if you get them straight after a water change, the combined stress of that, being caught, bagged up and put in your tank can push them over the edge.

The best time to get fish is the day before they get a water change at the shop, and at least 1 week after the fish have come into the shop.

Do a water change and gravel clean on your tank a day or two before you get new fish, and don't do another water change for a week after you get them, unless there is a major water quality issue.