[tkeracer619]

Water changes are almost useless to export large quantities of phosphates as most of the phosphate is bound to the calcium carbonate surfaces and not free floating in the water. You could change 100% of the water and the next day have the same exact tested number. Once they are under control and your bacterial colonies are strong regular water changes can help maintain them.

Definitely get the hanna 736 ulr phosphorus checker.

GFO is the best bet once you are in the tank but at this point like some others have said I wouldn't think too much about it if the tank was started recently. I would worry about keeping the tank stable and get into a regular maintenance routine. After that I would start investigating phosphates and dealing with them as you see fit. Sometimes it can take a long time to get them in check.