I have been using the advice from Mr. Barr's reply from below
I have a 55 gallon tank which is twice this size with bottled CO2 reading 30-35 ppm at the end of the photo period. There is 2.36 wpg and the tank is pretty full but not really with fast growers. I started doubling the above dose (because the tank size is doubled) but have since cut it back to the ¼ and 1/16 teaspoons respectfully. Using a LaMotte NO3 kit I notice that I am reading much higher than the 5-10 +- 1 as listed in the Estimative index. I do perform an approximate 50% water change weekly. I say 50% because I use a siphone drain not measured and I do not know the volume of substrate and driftwood but it is 50% on the glass. Should I change more water to re-set the tank more or lower yet the 4x per week dose amount to bring down the NO3 levels? It averages in the 17.6 ppm range from the LaMotte kit.plantbrain said:Back to your tank:
Yes, just follow the advice.
For a 100liter tank with high light:
Add every other day:
1/4 teaspoon KNO3
~1/16" KH2PO4 or 2-3 drops of enema
On the off day, add 5mls of trace mix(TMG, Flourish or equivalent)
Do 50% weekly (or larger water changes)
So 4 days of macro dosing, 3 of trace dosing per week.
This is very heavy dosing and can be scaled back with less light, but it will not harm a lower light tank either.
Make sure you have good CO2.
That's the main issue with your tank.