Dying Fish

[Quim]

Hello, I recently moved and since the move all my fish are dying. It has been 2 days since I moved the fish and I have 1 cory cat left, but dying, 3 ghost shrimp that seem fine and 3 assassin snail that aren't doing that great. My 20 g was established, I put all the fish in a 10 g and moved the 20 to where I moved, set it up and got it going. It ran for a couple days and I checked the water and all was good. 0 ammonia, 0 nitrite and 1 nitrate. I've lost 4 Guppys, 5 tetras and 3 about to be 4 cory cats. I think it was stress but I was hoping for some insight before I rebuild. I want to be positive my tank is safe before I add fish to it. Any help would be appreciated.

 

[Phranque]

My first suspect would be your nitrate test, and what test are you using? API reads in increments of 5, so are you using something more sensitive?
If you had all of those fish, shrimp, and snails in a 20g, There's no way your nitrate was only 1. It sounds like you may have kicked a bunch of stuff loose that was settled in the substrate, and your nitrates may have spiked.

 

[Quim]

I'm sorry I use an API test, but the color of the water was in between 0 and 5. When I moved the tank I drained it and removed all the gravel and put in new sand because I heard the cories would like sand better. So I couldn't have stirred anything up. All my fish are dead now, the snails look dead, but the ghost shrimp seem fine. I made a 3d background and installed it in the move. I read to fill and drain the tank like 10 times and let water soak for 24 hours and drain and refill and if your ph was good it would be safe. I did all that and waited until my all my levels before transporting the fish. Could it have been just stress. I only moved 20 minutes away.