100s on 1:35 holding 1:30 would be my suggestion.
In my opinion if you can make this set then you should be able to hold a much faster pace than 1:30 on a 1500. When I do pace sets I aim for a 2:1 swim to rest ratio and I find that's pretty difficult. So for a 1:30 pace that would mean a 2:15 sendoff. There's no way I could hold my pace with only five seconds rest.
100s on 1:35 holding 1:30 would be my suggestion.
In my opinion if you can make this set then you should be able to hold a much faster pace than 1:30 on a 1500. When I do pace sets I aim for a 2:1 swim to rest ratio and I find that's pretty difficult. So for a 1:30 pace that would mean a 2:15 sendoff. There's no way I could hold my pace with only five seconds rest.