What is the trick with level 2106?

For level 2106, the critical thing is how to make full use of fish given within only 23 moves.

Firstly, try to focus on clearing the bottom within 5 moves. Wrapped candies should be helpful there. Conserve all the two fish bags there if possible. (like this ↓)

Then the following moves should split into 2 directions:

For one, break the middle long cake of the top two lines, where afterwards you can possibly use the 3 fishes dropped from top. In that, any matches with vertically-striped candies may be helpful.

For another, break the rest section with horizontal-striped fishes, till the cakes on two sides are activated.

If you follow the steps above, for the best (at a small rate), you'll see the all the licorice removed, and the fishes rose up to eat ice layers on top, largely facilitating you to finish the level.

Remember, you may have to take a few attempts before all the things comes just come as wished. If you really want to pass it without any boosters, then, better to obtain some infinite health from activities!

Reply me if you have any questions. Keep trying and happy crushing!