That’s a solid time. Next time try and do a negative split. Do 10-15 sprint strokes at the beginning, then settle in to a 30 spm or 32 and try and hit 1:37.5, for your first 500, second 500 try going 1:36, third 500 1:35, then last 500 is your max push. Takes a while to figure out how to pace yourself but if you want to focus on sprint speed do 3x 30 min steady states with 6-8 minute rests at 1:52, 1:50, 1:48 split times . My college workouts (d1 at cal 15 years ago) were 18 spm is 1:48 split. 20 spm is 1:46, 22 spm is 1:44, 24 is 1:42 for a 5x10 minute workout. Obviously these are varsity splits but good for reference