How much weight

Depends how deep you are diving. Start with 6 lbs and see if you need more or less. You should be able to stop kicking at around 20-25 ft from the surface and float the rest of the way up.

I'm 235lb with full 3mm and use 10.5 lbs.

I use 3lbs for my 2.5mm shorty and im 195. 5'11"

I am 5'11, 175lbs, useing a full 3mm suit and use 4lbs. But I seldom freedive below 50fsw.
hau

Quote from hau

I am 5'11, 175lbs, useing a full 3mm suit and use 4lbs. But I seldom freedive below 50fsw.
hau

hau, at what depth does your bouyancy change when you use 4lbs?

I've been using four pound and am thinking of added two more. Any advice?

1. Try 1lb changes if you can to get more perfect/comfortable weight.
2. Diving weights are an underrated piece of equipment IMO. When I was teaching scuba I used ankle weights to keep my head up more to watch students better and used more weight than normal to enable me to control a student in the water better. Freediving I use a lead necklace to keep me flat or more head down in the water. I use a loose weight belt with weights free on the belt to slide into different locations as I need them, meaning while on the surface resting face up I slide all my weightsl around to my back and while face down in the water I let my weights slide around to my stomach. With a loose belt the surface dive is much easier as the weights slide towards my head and aid in getting me head down faster into the dive. All of this is unconventional and nonstandard weight belt usage, I know. But once you try diving with a loose belt you will immediatly understand what I am saying and realize how much more comfortable you are in the water not trying to stay face down with your weights on your back as an example.
3. Diving weights are more critical for freedivers IMO because we have no BCD to use to compensate for to much or not enough weight.
4. If you think about it, our weight belt is our body ballast system, much like a gun is ballasted to lie flat in the water.
5. IMO my weight belt represents a hazard to me and I will dump it to the bottom the second I have a problem so I can get back up faster/easier/safer. In my depths I can always go back down after a breath up to retrieve the belt.
Hope this helps.
hau

The deeper you dive, the less weight you wear and vice-versa.

You must be able to breath effortlessy in the surface and become negative half way down to the dept you intend to dive. It is a try and error thing until you find out the right weight for you. Everybody has a different body mass. The fatter you are, the buoyant you are (la mierda flota :D).

Try with the 6 pouds the guys told you, but take another additional weight (I would say 2#) in your float just in case you need it. It is a pain in the ass not having the right weight.

If you havent bought a belt, I strongly recommend a Cressi Marsigliaise rubber belt. This is if you are a freediver.

Marco said it perfectly. Great advice Marco:D

like the guys said, try out different weights and see what works best.

I'm 5'10, 175lbs, with a 3mm I use 8lbs for up to 60' or so, 6lbs for deeper stuff.