I smoke about 6 grams a day. Bong only. I usually won't feel stoned until the third bowl. For sure it'll kick in a little, but to get stoned? 3 or more bowls. If I smoke blunts or joints, then it'll be more.
There's no such thing as strains that don't build up tolerance. People claim Bubba Kush doesn't. Well I built a tolerance to it. I can be smoking Granddaddy Purple for weeks on end, try a new strain and get really stoned off it. But after a day of the new strain, my body has adapted.
We can talk about how each strain is different, how they have a different lineage, its indica, thats sativa, its a hybrid......... but when it comes down to it. The denominator is T.H.C. and it's the t.h.c building up on your spinal cord. Consider it like this, there are many different types of a certain vegetable, but that vegetable, no matter the family it comes from, will give you the same nutrients, of course there will be a variance, but the difference is not so different that your body will notice it when it's digesting it. The only difference you notice is taste and texture.
Same with weed.
The only way to lower your tolerance is to simply abstain for a couple days. Everything else is just bullshit. If you're a really heavy smoker. Abstaining for a couple days is ALOT for your body.
If it adds any substance to my opinion, I have been smoking consistently for about 9 years now.