Glo Fish Dead Overnight, Molly Fine

[screspo94]

Hello all,

I am new to the fish world and am trying to figure out where I went wrong. I have owned Betta fish for years and decided to try a tank with some new fish. I got 3 Glofish Tetras and a Lyretail Molly from the store yesterday. I went to bed at 2 AM and woke up to find the 3 Glofish dead and the Molly swimming around fine.

Test strip info:
Tank size: 10 gal
tank age: 2 days
pH: 7
nitrite: 0
nitrate: 0
kH: 120-180
gH: 60
tank temp: 78

Tank has filter and those round beeds (came with the tank), as well as a large bubble wall and a pump to help with water flow on the far side of the tank. Typical decorations and then crushed coral and pebbles for the bottom.

Any thoughts? My questions:

Is the Molly safe? I’ve pulled it out of the tank currently.

Thoughts as to what happened to the Glofish? Is it a water or a schooling issue?

I’ve removed the dead ones but do I need to completely clean the tank now?

Should and when should I get new fish?

 

[connorlindeman]

I don't think your tank is cycled.
What are your ammonia readings?

 

[Slaphppy7]

Welcome to TFF

A 2 day old tank won't be cycled, so the deaths may be from ammonia poisoning

 

[screspo94]

I don't think your tank is cycled.
What are your ammonia readings?

According to the test it is at 0

 

[Slaphppy7]

What kind of test kit are you using?

What is your source water hardness? Mollies are hard water fish, tetras prefer soft, not a good idea to mix the two.

Again, a 2 day old tank will not be cycled, unless seeded media is used from an established tank.