fish seem to be swimming bit erratic

Question
please had tank up and running for quite a few weeks.  bought some white minnows x 6 had them one week they all swam in a schole.  this week bought x 6 gold ones however they all seem to be swimming erratic all over the tank up quite high to the top.  and then up and down at the side of the glass rather than across.

they seem to be ok they look healthy and are eating ok is it just the newness of their surroundings do you think please

Answer
It is called chasing the glass meaning that they are bored. Almost all fish do this. Did you know puffers chase the glass by spinning around in circles?

What is your tank size? With two schools of minnows a 20 gallon would be the right size. In a small or undersized aquarium then is necessary boredom is inevitable.

If you have an empty tank it will cause extreme stress and boredom. Minnows need fake/live plants to hide, places to swim in and out of, etc. I recommend changing the decorations in the tank at least once a month to prevent boredom, to ease any territorial fish's aggression, and its healthy for the fish.

I mean, if you had to live in a room with everything the same every day of your life without ANY new entertainment you'd grow pretty bored too.

- Ash