You can get knowledge points by reading Fishing Magazines. Every Magazine contains knowledge points about fish selected randomly. Magazines may contain information about fish from a certain fishery or information about any other fish.

After opening magazines, players obtain knowledge points. Magazines disappear after reading (status: used).

There are 4 kinds of pages: grey, blue, golden and purple, each possessing different amount of knowledge points (grey - common, purple - legendary).
The amount of knowledge points for each page is generated randomly.

Every page contains:
a) number of obtained knowledge points,
b) current knowledge level and number of knowledge points concerning possessed fish,
c) number of required knowledge points necessary to start the training of another knowledge level

If you want to level up your current fish knowledge (after obtaining the necessary number of points) you have to go to the fishery where the fish appears or open a tab in the Fish Album.
All fish, which you can level up, have knowledge points marked green.
In the fish summary window, there is a list of actions which opens after tapping the tab on the right. You can train your fish knowledge by clicking the "Train" option.

Training time depends on your fish level. The higher the level the longer it lasts. You can have up to five active training sessions of fish at the same time. You do not have to be logged in all the time to keep up with the progress.

After a certain period of time, the training is finished and the reached knowledge level is permanent.
Increasing your knowledge level affects the number of your passive bonuses active during fishing:
a) Maximum weight of caught fish
b) Faster reeling in
c) Power Bonus
d) chance of finding a new fish perk