My new female betta fish is hiding. Is she stressed or scared?

Thanks for using Petco Pet Education Center, formerly Petcoach! This is most likely just normal behavior as he adjusts to his new environment. As he gets more used to you, he will become more interactive most likely. Good luck and have a great day!

Thanks for your question about your fish, and congratulations on your new family members! I didn't see how recently the tank was set up, but there are a couple of things that could be going on. I would start by checking your water quality - any abnormalities in water quality can make fish have abnormal behaviors, and the water looks a bit murky in the photos you provided. There may be parameters that need to be addressed depending on what you find. If you do not have a water quality kit, they can be purchased at the pet store or an aquarium store, or you can take a sample of your water in for evaluation to these places as well. Some will charge a small fee for this service, just so you are prepared. Also, with recent tank set ups, it can be stressful for fish as they are in a new habitat. I would recommend keeping the light on for only a few hours per day to start, as the bright lights can be shocking for them (since fish don't have eyelids). Gradually you can increase the length of time that the lights are on so that you reach a cycle of 10-12 hours of light and 12-14 hours of darkness for them. I hope this gives you a place to start, and I wish you and your mom the best with the new pets!

Bettas may hibernate or stay at the bottom of the tank if they are stressed or too cold. Making sure your filter is working properly and the tank is at the right temperature of 70-75 degrees F may help. Checking for any signs of illness and testing the water can also help clue you in to any issues. It would be best to make sure Kira is feeling well first before the stress of adding her to a new tank with a tank mate.

Like any creature moving into a new habitat at first they will be wary and nervous. I would give the fish a bit if time to settle in and become acclimitised to the new tank before worrying too much. If you try and not disturb them overly you will find that they gradually become more comfortable and start to explore the tank.

Lower the light, limit trafffic in front of aquarium, check water quality and adjust as needed. Give a safe structure for Salsa to hide if he needs security. If you have to do a water change, make it progressively not drastically. We do not want to stress him furthermore. Hope salsa feels better. Cool name for a beta.

Female betta sororities are not "bad". They can be tricky to set up though. A 75 gallon tank is more than adequate for 15-20. Try to get them as close to age and size as possible and introduce them into the tank as a group. Provide PLENTY of cover (plants, hiding spots). Initially, there will be some squabbles and nipping as they establish their own heirarchy. Remove any that are overly aggressive. A betta tank may be too warm for Corys. Bettas do best between 78 F and 80 F whereas corys like water a bit cooler, 65 F to 75 F. A spotted leaf fish would not be recommended. It would likely eat the smaller bettas once it is grown.

The best thing is to just provide a safe and quiet environment for them until the get more used to their new surroundings. With time, she will become more comfortable. Make sure to also provide a nutritious diet and fresh water to keep her immune system healthy.