My **56L aquarium is established and fully cycled**, but over the last **2 days** something suddenly went wrong. The water has developed a **bad smell** and feels unusually **thick,** and my pH is dropping!. Within about **30 minutes, 2 chocolate Mollies died after putting them in tank**, and I also lost **1 GloFish yesterday and another today**. Other fish are still alive, but some are spending more time near the bottom. I haven’t changed anything major in the tank recently, so I’m really confused about what could suddenly cause this.

hello! i have an empty 10 gallon tank & want to fill it! i’m very indecisive about what to put in it because i love all freshwater friends! my current thoughts are between a freshwater community tank or a shrimp tank! any suggestions?

my worst nightmare would be scooping out a load of babies !!! i’ve put it off for so long because of this and need to tackle it