1. Exhaustion: Molly fry (baby fish) are extremely active and may become exhausted from swimming around. They might settle at the bottom to rest and conserve energy.
2. Lack of food: If the fry haven't been fed recently or if they are not getting enough food, they might become weak and lethargic, causing them to rest at the bottom.
3. Water quality issues: Poor water quality, such as high ammonia levels or low oxygen levels, can stress the fry and cause them to become weak and sluggish, leading them to the bottom of the tank.
4. Hiding from predators: While molly fry are not typically prey for their parents, they can be vulnerable to other fish in the tank. They may hide at the bottom for safety.
5. Illness: In some cases, baby mollies laying at the bottom could be a sign of illness. If the fry exhibit other symptoms such as loss of appetite, lethargy, or discoloration, it's important to seek advice from a veterinarian or experienced aquarist.
Here's what you can do to help:
* Ensure adequate feeding: Provide frequent, small meals of high-quality fry food.
* Maintain good water quality: Perform regular water changes (25% weekly) and use a water conditioner to remove harmful chemicals.
* Consider a breeding box: If you have other fish in the tank that might prey on the fry, consider using a breeding box to provide a safe haven for the young ones.
* Monitor for signs of illness: If the fry are exhibiting other symptoms, consult with an expert to rule out any health issues.
By addressing the potential causes and providing proper care, you can help your baby molly fish thrive and avoid spending all their time at the bottom of the tank.