Blueberry is a very easily stressed plant that doesn't like hard water.I read it likes a Ph of around 6.0 and doesn't like the Ph fluctuating try keeping the Ph steady and have also read that it droops badly with cold water temps.Blueberry has lovely hard round buds.I have read that this plant really does need sufficient room to grow as it really thrives during flower,but as lip says you will have to post more info on your set up. the postman.