Originally Posted by Hardstuff
You are looking for trouble avoiding K, P. & N. If you are running pressurized CO2 & your lighting is up to speed you will be making an algae farm without The big nutrients. Plants need proper nutrients to compete with the algae. Algae can operate with very low nutrient levels & out compete your plants. It is a myth to think that keeping low Nitrates & phosphates will keep algae away. It is actually the opposite.
I would dose dry ferts , which when mixed are really liquid ferts. The tank needs to stay above 10 ppms of Nitrate at all times. PO4 should stay between (.5-1.0) ppm at least. K every other day at least. The tank will need good flow & filtration to keep BGA away as well. The lighting needs to be between 6500-6700k or your looking for trouble know matter how you cut it.
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.