Dying neon tetras

[prof]

Why is it that my neon tetras keep dying even though I do water changes weekly? The neons look okay at the shop but when I put them in my tank(after quarantine), they will die one after the other. Please help me!!!

[Quixotic]

Merely describing your problem in general isn't going to help because we can't imagine what is the setup of your tank like. You will need to describe your tank setup more in detail in order for the members to help.

What is the size of your tank? What are the inhabitants and their numbers? How long has this tank been set up? How long was the tank cycled before adding the fishes? It this a planted tank? Do you inject an CO2 if it is a planted tank? Any gravels (brand of gravel)?

What filter (brand) are you using? What are you using for the filter medias? What is the pH, ammonia, nitrite, nitrate, temperature readings? What do you dose after each water change (e.g. de-chlorinator, water conditioners)? What is the percentage of the weekly water change?

Provide as much information as possible. If possible, a picture of the tank as well. Otherwise, it is just hardly possible to offer any useful good advice.

[prof]

Ok then .... my tank is a 3 footer with 6 lemon tetras, 20 Rasboras , 4 ottos, 6 X-ray tetras. Yes it is a heavily planted tank with CO2 using quartz as the gravel and was set up for 6 months already.

I'm using Fluval 204 with sponge, ceramic rings and peat at the last compartment.
pH between 6-7, temperature 28c nitrate...???....I do 20% water changes every week

Hope this info is sufficient

[Quixotic]

Well, not quite but at least something to work on. You didn't mention how many neon tetras you added, so how many are there? Your bioload without the neon tetras seems good.

What about ammonia, nitrite and nitrate? These are the potential major issues for fishes. Any readings?

Is the pH a recent reading? If it is not, some ceramic rings are said to raise pH. I would also suggest to perform pH readings at different intervals, just to be sure that it is not the issue of pH swing.

For your water change, do you add any de-chlorinators/water conditioners, or just straight from the tap?

[tango]

Ok then .... my tank is a 3 footer with 6 lemon tetras, 20 Rasboras , 4 ottos, 6 X-ray tetras. Yes it is a heavily planted tank with CO2 using quartz as the gravel and was set up for 6 months already.

I'm using Fluval 204 with sponge, ceramic rings and peat at the last compartment.
pH between 6-7, temperature 28c nitrate...???....I do 20% water changes every week

Hope this info is sufficient

when your neon tetra dies, is there any white spots at the tails/fins. Beware of the high contagious neon tetra disease. Sometime the fishes are already infected in the shop, only suprressed by medicine.

tango