Every tank is different. I have run a tank without npk for three years and had no algae. NPK in my tank causes algae as I have a large fish load. I also have gone without any measurable nitrate in my tank for 3 years. And grown a forest without it being at measurable levels. Let me stress that I understand that nitrates were present. My point is they just were not measurable with my liquid test kits.
Also guys while I appreciate the advice. I know my tank and my water parameters and really don't want or need (and I mean this in the most respectful way) convincing about npk when I stated to begin with that I was looking for a liquid fert that didn't contain any npk.
You bet no tank is the same, as for me I did experience algae outbreak in the past when I was not dosing enough NO3 and PO4. Recently in november I did grow and algae farm when injecting pressurized CO2 about 15ppm and not fertilizing at all, but my tank population was small.
Algae disappeared after I began dosing nitrates and phosphates.
Personally I would say do not assume that the fauna sends enough phosphates/nitrates in the water especially when injecting CO2, if it does, it is merely luck. Measure what you can, and watch plants/algae's behaving carefully.