I would stop dosing Phols extra and Zeofood immediately. Those 2 products are designed to be used sparingly in a ULN system. They will raise your nitrates quickly. Honestly, I would stop dosing all organic supplements, except for the Zeobak, until you see a drop in your nitrates. If you stick with bak, start, sponge power and zeolites along with the water changes and a good skimmer, I think you will see a decrease in your nitrates. But the biggest culprits are phols extra special and zeofood.
If you want to try something else, I would try a macroalgae reactor. They are cheap to make and if it doesn't work due to the already low phosphate levels, you can take it off line. The Biopellets, I think would be too much for your system ( or any system).
The one thing that gives Zeovit a bad name is all of the options (blue bottles) you have. People start dosing this or dosing that because they are available and they read or see other peoples success with it and their system get out of wack, then they blame Zeovit for it. They don't understand it takes a while to get to that ULN state and the organic products are made to be used when you are at the state. If you take it back to the basic Zeovit system (lites, bak, start and sponge) I think your Nitrates will drop. Once you achieve that ULN state and your corals start to turn pastel ten you manage the colors with the organic supplements (Phols, Zeo Food, AA, CV, AG, CB) . This is just my suggestion.