rowing technique

Time in the gym, any gym, will involve doing exercises and movements under load. Without an understanding of form and technique, you might as well be playing chess to grow muscle.
Though simple in theory, if you haven’t been taught the one skill (the rowing stroke) properly, it’s easy to butcher it and make all sorts of crazy mistakes.
Proper pressure application will allow you to recruit the strongest muscles on every pull.
Teach your body to achieve and maintain the correct positions, so you get the most from every stroke.
The basic mechanics of rowing are not fundamentally different than those of lifting weights.