New Opaline Gourami

[Bluegrunt25]

Hey guys
Yesterday i bought 2 Opaline gouramis to go in my 4 ft tank with my guppies
For most of the first day they swam around and ate some of the bloodworms i gave them
But for this second day one of the gouramies stays on the ground Except to eat and to go up the top and get air.
The other thing was that when it would go back to the ground to sit it kinda looked like the tail was sinking but i dont know ifthats what its meant to look like.
The other one swims around and does all the things i expect a fish to do,

It has only been 1 day so i dont know if this one is just getting used to the tank or something but i just wanted to make sure there is nothing wrong

thanks

 

[KittyKat]

Water readings, etc, please..

 

[Bluegrunt25]

Water readings, etc, please..

Im in australia so its dark outside and i dont own a nitrate etc test kit will have to buy one tommorow,
but the PH level is at 6.9 And my water Temp is at 27 Degrees
i also 2 days ago did a 20% water change and a few days before that a 50% Water change