rubbachicken:
appart from diving more often are there other ways of getting my breathing better, yoga or what ever
breathing exersizes, my breathing is better that it was but i'd like to try an help the air my tank last longer
That is a hard quetion to answer. With 155 dives you are no newbie and you say you have your bouancy and weighting down pat. To answer your question we need to know more information:
1. What is your SAC rate now?
2. Diving dry (that will use air) or wet?
3. Normal temp range of your diving?
4. Normal depth?
5. Age
6. Gender
7. What are you doing when you dive? Sightseeing, hunting, photography, working?
Are we talking a SAC of 1.2 SCFM or 0.5 or 0.40 or what? There may not be room to improve. You do have to breath every once in a while.
I did a survey here a few months back on what is a normal SAC. It appears to be in the 0.40 - 0.48 range for males.
My personal best was a SAC of 0.28 SCFM but that was an exceptional dive with a very shallow average depth and very short due to buddies equipment malfunction (1st stage leaking and not from the O-ring area either and breathing hard). My best outside of that is some dives at 0.32 - 0.36 SCFM. My normal SAC is in the 0.38-0.42 range. In reviewing my SAC rate, I have noticed that since I quit running every day a few months ago, my rate has gone up a tad bit and where I was seeing a lot of 0.36-0.38 I am now running closer to the 0.40-0.42 range. On some dives, particularly Lobster dives where I am pulling a bug out of a hole (those guys are strong) my rate is higher and can hit 0.48-0.50 Normal temps here are 54-65F.
So give us a bit more to go on.