Originally Posted by
Medium9
Wild flish tend to not do well in a tank, for a variety of reasons. Don't expect them to get very old.
It's also a terrible idea to mix fish from different waters, and especially bad to add wild catches to a tank that only ever had tank-bred fish. Reason: You introduce pathogens and algae the other fish might not be used to, and cross-contaminate them with all kinds of stuff. (Saying this just in case.)
Also: Get a proper filter pump, and do a weekly water change. Especially with wild catches. Meaning: Pull out ~50-70% of all water and replace with fresh tap water of suitable temperature. There are special hoses/nozzles for this, many also designed such that you can suck out a bit of the grime that builds up at the bottom. But no fish.
Also make sure you have proper lighting on a programmable outlet and a lot of plants suitable for the water.
Magnetic glass cleaners are a godsend.
Do not EVER mix fish that are natural enemies!
Some fish are shy by nature. Reserach what fish you have, and provide stones and other hiding opportunities if needed. (They also look cool!) Otherwise you condemn them to life in constant stress - also not great for longevity.
Fish have a fairly easy tell if they feel alright: The more vibrant and intense their colors, the better they are. Usually.
Fish tanks are a buttload of work. Have fun!