Most commercial fishing arrow shafts weigh 700-1000grains or so. I've never weighed mine but I had a friend who deer hunted with them and he said his were about 800gr finished out. The additional weight helps them go deeper in the water, but from experience I can tell you that if you're shooting more than a foot deep into the water it is VERY hard to aim because of light refraction. I've shot a few carp with cedar arrows and they worked fine though the carp broke them pretty easily. I used to drill a hole in the arrow near the tip and one near the nock. I'd thread the line from the "reel" through the nock hole, tie it off with a lot of free line and then wind that line around the arrow several times before tying it at the point end. Then, when the carp broke the arrow, at least I got to pull them in. Now I use glass arrows, even with my primitive bows, though it isn't very primitive.
George