I have been dosing with EI using the basic macro and micro solutions from James' Planted Tanks page. The macro solution (Potassium Nitrate and Potassium Phosphate) I add 6ml every other day except Saturday which I believe works out at 3ppm per day or 18ppm per week (I have about 80 litres of water).
My tap water already contains 30ppm nitrates. I am having very high Nitrate reading at the end of each week (80ppm+). Before I started EI I was getting readings around 10ppm. I believe the objective is to aim for 20-30ppm nitrates. I do a 50% water change each week to reset the system. I know that testing is not always necessary with EI, but I am just trying to get a feel for how the system functions.
I am thinking that I should reduce the Potassium Nitrate in the macro solution as it is not needed. Is this correct? Could the tap water in addition to the macro solution explain the high nitrate readings? Or could it be something else?
My ammonia and nitrite are always zero. I am using Easycarbo (1.5ml per day) and have just above 2 wpg lighting. The tank is about 50% planted. I also have a slight green algae problem developing.
Any thoughts? I am a novice at this sort of thing so apologies if the question seems trite.