Sick guppie help

[TheRock]

Hi guys I'm new to this world, awesome to find some experts,

I set up my 20gallon 30 wide about a month ago upgraded from a 10 gallon I also moved my neon tetras as well has some of the water to my new tank,
got about 5 guppy 2 males 3 females
2 weeks after the tank was setup

Within last week 3 of them died. So I'm left with a couple, today I have noticed that my male has a yellow spot on the end of his fin and he is not moving a lot
All my other fish is fine

Right now I have
X8 neon tetras
X2 guppys plus (3babies)
X7ghost shrimp


Went to local store to test water quality everything seems ok

What am I doing wrong? Pls help


Sent from my iPhone using Aquarium Advice

 

[TheRock]

. That's my tank setup


Sent from my iPhone using Aquarium Advice

 

[TheRock]

Also I have drift wood, a couple of plants air filter and a 50 gallon water filter


Sent from my iPhone using Aquarium Advice

 

[emerald76]

It's probably cycling, read up on cycling here at the forum. You need exact readings not "okay"


Sent from my iPhone using Aquarium Advice