They are "Planaria worms". They are harmless but they will become more numerous and eventually you will have to do a complete strip down and clean out of the tank in the not too distant future.
Cuz it is used to the small tank
a small fish tank.
no because there on fire
Planaria worms will occur naturally if you have a well balanced/planted tank and continued occupancy by larger species of fish (like Cichlids) that will not eat them because they are too small.
It doesn't matter what tank they are in, it is the food you feed the fish.
wipe it....(:
It means the tank should be cleaned.
No, newts eat small invertebrates.
Yes you can.
The white scale on the inside of the fish tank is from a buildup of minerals that were in the water.
yes
No.