Congrats on having your SPS take off. That is an awesome thing to happen. Personally I've used 2 part, Calcium Reactor, Kalk Stirrer. The 2 part worked good and I've got an SPS buddy thats had great sucess from it. Personally I hated to consistantly buy mix, monthly, making sure my dosing pump was set correctly and making sure my dosing line did not clog up. The Calcium Reactor along with a Kalk Stirrer , other than the initial set up cost, works great and aother than a tweak here and there runs for months without having to mix anything. Less maintance to me was the way to go. Not to mention your getting your trace elements from your reactor withough having to dose anything. My levels stay stable and seem very constance. I'm not always home to add two part and with the Cacium reactor it seems to run itself for about 6 months before I have to add media.
If your getting the growth then IMO you going to have to use 2 part or a Calicum Reactor and both can be used in conjunction with Kalk. Good luck