I pull it out by hand. I reach in pull a handfull out, then dip my hand in clean water before putting my hand back in the tank everytime. After doing this for a while i would do a water change. I did this every few days and I had almost all of it gone, and I had a lot, in about a week.
How old is your tank? If you have a lot of HA I would thi k you might have a phosphate problem. Do u use ro water? How much do u feed? What size tank, and what is your bioload?