I put the water in the hull as my last option. Start by just examining the whole kayak. Next check the scuppers by plugging the underside and filling them up with a cup, you need to have the inside of the hull dry to start and look inside for seepage. Plug your in and out of the kayatank, first inside the bladder, fill it up and check, then plug it from the outside thru hull fittings to check the hoses and fittings. I have a sturdy stand to use, most people would just set it on dry pavement and put water in the hull.
__________________
|