Is it safe for me to take 900mg of seroquel (quetiapine) for. my bi polar n sleep?

Bipolar disorder: I hope you are under the care of a psychiatrist. Only he may be able to answer you . Treatment of bipolar is very complex to the least ! manic , max recommended dose is 800 mg /day, and for acute depressive max 600 mg/day. Do discuss with your doctor. 900 mg/day may be just fine for the manic episode when pt is very energetic, and not able to sleep. Good luck.