Why are my fish dying?

[smwhang]

Hi,
My 2 cents worth here;
Its obvious that overfeeding is the culprit here, I'm guilty of it too at times....

Suggest that you start the tank all over again.
Strip everything wash and sanitise it with a mild solution of hydrogen peroxide...3% food grade is good. Kills all bacteria.

Properly understand how to cycle a tank from the beginning, starting with your equiptment required.
I'd strongly suggest you add a fluidised bed filter as a biological filter for your ( i have one too!! I love feeding fish) urge to feed them hungry fish.
Very cheap and easy to connect to your filter outlet; dependant on what filter you have or want to purchase.

I have a UP Aqua EX120 connected to mine. Looks cool too when it's working and you don't have to clean it...the longer you use it, the better.

Anyway, after cycling the tank properly; you may use Tetra SafeStart to start the biological process....it takes only 24 hours...i use it and it drops the NO2 and NO3 to zero in 24hrs.

Then you put in your fish and what nots..

You need your 6 in 1 test strips to help you monitor your water parameters. This is important. Then share with us your progress.

Its always distressing for us to hear of a fish keepers' tragedy...would like everyone to succeed and enjoy this hobby.

Awaiting your success then mate!

[smwhang]

You may consider starting out in low tech without CO2 injection because CO2 injected tanks are more complicated for a beginner.
I know it looks cool and everything but trust me; its more variables to maintain a balance for from a beginner's standpoint.
You can always add on when you're more into the understanding of planted tanks.

I used to have a high tech tank but now have stopped CO2 injection because it's less troublesome....less pruning and even less algae problems...
I should share my observations in detail...

Anyway, i blather on...begging your forgiveness.
Good luck and don't give up!