we're individuals. Our bodies are different and can tolerate different amounts. You may think you've completely detoxed but maybe you're still detoxing w/o feeling it. That's why you're getting sever bloating. Don't increase until your body can tolerate it, even if you have to hold at .5 for a month or more. My mom got to 3 grams, but it took her almost 3 months to do it. Everyone is different.
In addition there's another question I noticed later down the thread of how can some of us go higher? Well I'm only on chlorella not spirulina so that may be a reason why. They both contain tons of protein. I don't do spirulina because I have Grave's disease and it has been know to sometimes stimulate the immune system in a negative manner for those that are autoimmune. So I am just cautious with it. Others have noticed the opposite effect but I just don't want to risk it.
I'm sure you'll be able to increase, just not as much because you probably already have so much spirulina.