29 gallon progress and a few questions...

Colin_T said:

Are you sure the black widow/ skirt tetra killed the other fish and they didn't die from a disease or poor water quality?

Do not add fish to a tank that fish died in until the tank has been stable for a month or more. If the fish died from a disease and you add new fish now, there's a good chance they will die too. Wait at least a month before adding any new fish.

You need to check the water quality for ammonia, nitrite, nitrate, pH and GH.

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

Did you add anything new (besides the black gravel) to the tank in the last couple of weeks?

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You have rainbowfish (Melanotaenia lacustris) and a swordtail in a tank with tetras. The rainbows and swordtail do best in water that has a pH above 7.0 and a GH above 200ppm. The tetras usually do better in water with a pH below 7.0 and a GH below 150ppm.

Rainbowfish should be kept in groups of 6 or more. Rainbows need some plant matter in their diet.
Tetras and danios need to be kept in groups of at least 6 and preferably 10 or more.

It's possible your black skirt tetra got agro because it was the only black skirt in the tank. However, the white skirt tetras are the same species just a different colour, and they normally school together.
Before this happened, did the black skirt swim around with the white skirts?

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As for improving the aesthetics in the tank, I would put a picture on the back and remove some of the rock and wood so there is more open space in the middle.

Click to expand...

Colin_T said:

Are you sure the black widow/ skirt tetra killed the other fish and they didn't die from a disease or poor water quality?

Do not add fish to a tank that fish died in until the tank has been stable for a month or more. If the fish died from a disease and you add new fish now, there's a good chance they will die too. Wait at least a month before adding any new fish.

You need to check the water quality for ammonia, nitrite, nitrate, pH and GH.

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

Did you add anything new (besides the black gravel) to the tank in the last couple of weeks?

---------------------------
You have rainbowfish (Melanotaenia lacustris) and a swordtail in a tank with tetras. The rainbows and swordtail do best in water that has a pH above 7.0 and a GH above 200ppm. The tetras usually do better in water with a pH below 7.0 and a GH below 150ppm.

Rainbowfish should be kept in groups of 6 or more. Rainbows need some plant matter in their diet.
Tetras and danios need to be kept in groups of at least 6 and preferably 10 or more.

It's possible your black skirt tetra got agro because it was the only black skirt in the tank. However, the white skirt tetras are the same species just a different colour, and they normally school together.
Before this happened, did the black skirt swim around with the white skirts?

---------------------------
As for improving the aesthetics in the tank, I would put a picture on the back and remove some of the rock and wood so there is more open space in the middle.

Click to expand...

Colin_T said:

maybe get rid of the black skirt tetra and don't get any more because they are renown fin nippers.

re: the blue gourami. Are you looking at a blue dwarf gourami or a blue/ 3 spot gourami?
Dwarf gouramis should be avoided because they regularly carry TB and the iridovirus, neither of which can be treated.
A blue/ 3 spot gourami could cause problems to the blue rainbowfish (Melanotaenia lacustris).

Click to expand...