Nice bike but I wouldn't worry too much about an extra kilo as long as you are on a typical triathlon bike course. Take a look at this page where you can change the input data to see where the cost in efficiency lies. I'm thinking that on a flat course the kilo is costing you at most 2 watts. If you are doing a lot of hill climbs the equation changes https://www.gribble.org/...g/power_v_speed.html
It's all about bike geometry, body position and the ease by which you can comfortably maintain it. Then make sure you don't muck it up by hanging a bottle on the down tube or something silly like that.
"Aquabike is a swim then sleep session on aerobars ...."