Hi Fay, I'm not totally familiar with what you're doing and your system, however I would hazard a guess that dosing start twice daily will help, and turn off the skimmer for an hour when you dose bac and food, but no need when you dose start.
Seems to me your nutrients are way higher than should be expected at this time, wonder if your zeo rock is already exhausted and could use a change.
But start is the big Po4 killer, so dosing that twice daily may help. Just monitor the Po4 as when it does start to drop, if there is a sudden sharp drop to almost zero, can damage some of your livestock.
Also, are you cycling your reactor on 3 off 3? It is the anearobic stage that will really pull nutrients down.
Also people measure what they should dose by tank size. But really the nutrients are created by what we feed the tank, not how big the tank is. So if you have a big bioload and feed heavily, may need to look at treating as if a larger tank.
Hope that is some help, and that nobody going to kill me if I got it all wrong