How to know what weight you should be lifting?

[Prophet]

I've been following a 3 day split program that uses sets of 4 X 10.

I've been doing this for 3 weeks and seem to be getting on OK however I'm concerned I'm not lifting enough.

The first 2 sets I'm fine and reach 10 reps without any problems, then the 3rd set I'm usually at the 6th rep when I start to struggle. The last set usually ends up with me getting to 7 then having to stop.

From memory I'm lifting the following:

Dumbell Incline Press 12.5KGs
Pec Deck 49KGs
Barbell Curls 20KGs
Bench Press 30KGs
Hammer Curls 12.5KGs
Seated Leg Press 80KGs
Calf Raises 80KGs
Seated Leg Curls 70KGs
Shoulder Press 49KGs
Lat Pull Down 49KGs
Wide Grip Seated Row 56KGs
Cable Pull Downs 49KGs

I'm going to tweak the routine as I'm doubling up on muscle groups but for now I'd like opinions on my weights and if I should adjust the amount and set/reps.

 

[Prophet]

Thanks for the advice

I've notice my form has improved over the last week. I'm noticing what I'm doing wrong and correcting it.

I'll give what you've suggested a go.