Sitting At The Bottom

[HeilBond]

Hello,
I got 4 Bettas a little over a week ago, one male and 3 females .(Yes,tank was cycled)  One of the females is acting oddly,sitting at the bottom and sometimes swimming up and staying there,motionless(She doesn't move her fins or anything). While the other fish basically fight over food,she shows no interest in it. I have to put food right above her for her to eat.
I doubt it could be the males fault,as he barely shows interest in the females,just protects his bubble nest when they get too close. Nobody bullies her in the tank.
I keep them in a 10 gallon heavily planted tank with filtration,room is always very warm so the temperature in the water warms up naturally(around 24C or 75F)...
What could be wrong?
 

 

[Wildbetta]

Number 1 -- your setup is heading for disaster.  Male and female bettas should never be house together except for spawning and only for as long as it takes for them to spawn.  Bettas are really aggressive especially to each other.  This includes females who can be more aggressive than males.  Many a breeder looses fish when breeding so it is always touchy.
 
Number 2 -- When keeping female bettas together, you need 5 or more to keep the tank somewhat peaceful.  The more females keeps the aggression level down.  It spreads the bullying out among all of them that way there is not one fish taking the brunt of the aggression.
 
Number 3 -- You need a heater in the tank to keep the temperature a steady 78F min or 82F is actually better.  Even if your room temperature is room - understand that water temperature is always lower than room temp. 
 
Now that I have addressed the issues with your tank, I will address the problem you are now facing.  That female is very stressed and obviously the one out of the three that is the scape goat of the aggression (whether you see it happening or not - it IS happening).  The fact that the male is guarding a bubblenest is a bad sign as a male will kill a female that threatens his nest.  Most people do not understand the aggressive body language that bettas display to each other and then end up with death in a tank they thought everyone was getting along in.  The best solution is to remove your male to a tank by himself and add a couple more female bettas to the 10 gallon.    

 

[ncguppy830]

everything that she said