Not needing air for buoyancy control ?

[gmerick]

Compensating for only 5 lbs of air consumed is very easy for a large frame person. I have a measured lung capacity of > 5 liters. I dive with all my weight (3kg) on my shoulder blades. I maintain horizontal trim with the tank full or empty. The first post indicates the OP has achieved this same neutral buoyancy.
It is entirely possible when correctly weighted to dive a 11l aluminum cylinder with no BC, but safety wise not recommended.

 

[johndiver999]

It's not a competition. Clearly the OP's weight was dialed in about perfectly, but it almost certainly would have been an easier, more relaxed and safer dive, if the diver used a little air in the BC when they first got to depth. I'm not a big fan of drastic manipulation of a natural or optimal respiratory cycle to play silly games.
On the other hand, it must be comforting to the OP to know that should his bc fail, he will be more than able to deal with the situation - in that specific configuration.

 

[Chavodel8en]

Sorry if I didn’t explain myself well

I was inflated on the surface and vented all air on the way down

After my safety stop and as my head was breaching the water I added some more in.

I was wearing 6lb of weights

Then sounds like you had good weighting, good buoyancy and good habits. What you describe is the ideal. Dump air to descend, and no need to touch the BC's buttons until you're on the surface. You adjusted your depth during the dive by swimming or using your lungs -- perhaps without even thinking about it. No problem at all.

Also no problem to adjust a bit during the dive, but in this case, you didnt need to. Its also easier for you to do in warm water. With my 8 mm wetsuit, I need to adjust my BC right after I descend -- or else I'll be too heavy, and occasionally during the dive.

 

[Atvmx51]

Focus on your breathing. Breathing affects your buoyancy more then you. Realize

 

[MidOH]

With an empty Al-80 and no trim weights, I'd probably have to ascend feet-first, finning all the time, to maintain the 10m/min rate.

Been there. Done that. Lol.

 

[ZzzKing]

My teenage daughter typically finishes her dives w/ 1400-1500 psi in the tank so she can easily compensate for that buoyancy swing (2-3 lbs). Me, I am at around 600-700 and could compensate but dumping a little air during the latter part of the dive makes for a more comfortable safety stop. Sounds like the OP is very close on proper weighting for warm water diving.

Keep in mind that prior to the 70's, buoyancy compensation devices were not widely used and the LP 72's used at time were ideal to mitigate buoyancy issues.