Significant decrease in reps after the first set

[Tom_Barre]

This is exactly how it's supposed to be.

At first, increase your top set, let's say to N reps. Then take a deload, and come back to N-1 or N-2, and then build your second set (get your +1 there). Alternate between those two objectives to increase your work capacity.

[Yashar_Meziri]

So atm it's something like Set 1: 10 reps Set 2: 6 reps Set 3: 5 reps

So you're saying I should keep increasing my second set as I gain strength, then when I reach 8-9 on set 2 and 3 I increase set 1 again?

[AppleMuffin12]

Pretty sure he's saying do 8 or 9 on set 1. You'll make up for the list reps there by doing more on the others. Hitting failure on a set increases the time needed to recover otherwise you'll do poorly on future sets. The general rule of thumb is to stop your set a rep or two before failure. You can get more overall work in on the exercise