Have you looked into reactors or possibly incorporate a refugium into your system? A refugium would help boost PH, and provide a house for pods to populate, and reduce nitrate and phosphate
Carbon dosing will lower both but will lower nitrate at a faster rate. So if phosphates are very high might be beneficial to lower those first with something like a media bag of phosguard near your return pump. Then when say .15 ppm switch to another method to lower both whether or fuge or carbon dosing. Go slow with whatever method you chose.
Id take a macro algae outbreak of any kind over dinos any day.