Guppy fenale at the bottom of the tank with a male

[Zené]

Hi everyone.

Why is my guppy female at the bottom of the tank? I noticed this morning that she was not swimming around and seems to have one male staying with her at the bottom of the tank

She seems pregnant but not too far along.

Should I be worried?
Please help!

 

[Colin_T]

Do a 75% water change and gravel clean the substrate.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

Add lots of plants to make the fish feel more secure.