Vodka dosing.. HELP!

[dynamite]

I've been dosing vodka and Microbakter 7 for 4 weeks.. I started with 0.5ml in the first week then went up to 1ml in the second week and when I got to 2ml I started seeing this white film on the glass.. So I cut my dosing to 1.5ml.
I keep getting the white film and I don't know if I should cut my dose again.

My phosphates are 0.03 (Hanna Phosphate Checker) and my Nitrates around 20-25.

Before I started dosing vodka I had them around 30/40ppm
I never had Nitrates soo high before. I used to have them at 0ppm.
I went to FL for a month (It's been like 8 months) and then to Peru (6 months ago) and my neighbour took good care of my fish, he top-off the 1st two weeks with RO/DI and the other two weeks with tap water and he probably overfeed the fish.
I came back to an amazonas and diatoms everywhere! I have no more hair algae but I'm still fighting with some diatoms on my sand bed.. I want to get my Nitrates back to 0! And I can't seem to get them under 20ppm

Any help would be greatly appreciated