Probably not the most accurate, but interesting how you can use Chat GPT
Question #1:
Calculate N03 ppm per ml of APT 3 in my 75 L tank. This is the ingredient list of APT 3 Liquid inorganic macronutrient fertiliserNPK (Mg) fertiliser with micronutrients and trace amounts of Boron (B), Copper (Cu), Manganese (Mn), Molybdenum (Mo) and Zinc (Zn). 0.7-0.9-7 (+1.6)0.7% Total Nitrogen (N)0.7% nitric nitrogen 0.9% Total Phosphorus pentoxide (P2O5) 7% Total Potassium oxide (K2O) 1.6% Magnesium oxide (MgO) 0.09% Total Iron chelated by EDTA, DTPA and EDDHA. All nutrients are completely water soluble.Ingredients
otassium sulphate (CMC1 CAS n°7778-80-5) Potassium chloride (CMC1 CAS n°7447-40-7) Magnesium nitrate (CMC1 CAS n°10377-60-3) Magnesium sulphate (CMC1 CAS n°7487-88-9) Potassium phosphate (CMC1 CAS n°7778-77-0) (copied and pasted from 2hr aquarist website)
Thought for 30s
Using the maker’s own guidance: a standard daily dose (3 mL / 100 L) adds < 1.5 ppm NO₃. Scaling that,
NO₃ from 1 mL into 75 L≈1.53×10075 = 0.67 ppm (max)\text{NO₃ from 1 mL into 75 L} \approx \frac{1.5}{3}\times\frac{100}{75} \;=\; 0.67\;\text{ppm (max)}NO₃ from 1 mL into 75 L≈31.5×75100=0.67ppm (max)
So a good working figure is ~0.6–0.7 ppm NO₃ per 1 mL into 75 L. The 2Hr Aquarist
This also lines up with the label chemistry (0.7% total N), which—depending on the liquid’s density—implies ~0.4–0.7 ppm NO₃ per 1 mL / 75 L. That’s because 0.7% N ≈ 7 mg N per mL (if ~1 g/mL), or a bit more if denser; converting N→NO₃ (×4.43) and spreading over 75 L lands in that ~0.4–0.7 ppm band.
Questions #2:
"so i started with about 1 ppm nitrate in my tank, did 70% water change, then added 2 ml of APT 3 immediately and then added 1 ml everyday on monday, tuesday, wednesday and today thursday. I tested nitrate today and it is 0.2 ppm. I want to know how much my tank is consuming also take into consideration nitrate generation from the tank fish/snail"
Thought for 1m 7s
Got it—let’s back-solve your tank’s nitrate uptake from what you actually did.
Final NO₃ after 4 days:
0.3⏟after WC+3.9⏟dosed−4U⏟4 days uptake=0.2⏟measured⇒4U=4.0⇒U≈1.0 ppm/day\underbrace{0.3}{\text{after WC}}+\underbrace{3.9}{\text{dosed}}-\underbrace{4U}{\text{4 days uptake}} = \underbrace{0.2}{\text{measured}}\Rightarrow 4U=4.0 \Rightarrow \boxed{U \approx 1.0\ \text{ppm/day}}after WC0.3+dosed3.9−4 days uptake4U=measured0.2⇒4U=4.0⇒U≈1.0 ppm/day
Net consumption ≈ 1.0 ppm NO₃ per day.
This already includes whatever nitrate your fish/snails are creating—i.e., your plants+bacteria are removing ~1.0 ppm/day after bioload is accounted for.
Typical bioload generation in a moderately stocked, fed 75 L might be ~0.2–0.4 ppm/day (ballpark). That would put gross uptake around ~1.2–1.4 ppm/day. If your stock is very light/heavy, shift that number down/up accordingly.
Question #1:
Calculate N03 ppm per ml of APT 3 in my 75 L tank. This is the ingredient list of APT 3 Liquid inorganic macronutrient fertiliserNPK (Mg) fertiliser with micronutrients and trace amounts of Boron (B), Copper (Cu), Manganese (Mn), Molybdenum (Mo) and Zinc (Zn). 0.7-0.9-7 (+1.6)0.7% Total Nitrogen (N)0.7% nitric nitrogen 0.9% Total Phosphorus pentoxide (P2O5) 7% Total Potassium oxide (K2O) 1.6% Magnesium oxide (MgO) 0.09% Total Iron chelated by EDTA, DTPA and EDDHA. All nutrients are completely water soluble.Ingredients
otassium sulphate (CMC1 CAS n°7778-80-5) Potassium chloride (CMC1 CAS n°7447-40-7) Magnesium nitrate (CMC1 CAS n°10377-60-3) Magnesium sulphate (CMC1 CAS n°7487-88-9) Potassium phosphate (CMC1 CAS n°7778-77-0) (copied and pasted from 2hr aquarist website)ChatGPT said:
Thought for 30s
Using the maker’s own guidance: a standard daily dose (3 mL / 100 L) adds < 1.5 ppm NO₃. Scaling that,
NO₃ from 1 mL into 75 L≈1.53×10075 = 0.67 ppm (max)\text{NO₃ from 1 mL into 75 L} \approx \frac{1.5}{3}\times\frac{100}{75} \;=\; 0.67\;\text{ppm (max)}NO₃ from 1 mL into 75 L≈31.5×75100=0.67ppm (max)
So a good working figure is ~0.6–0.7 ppm NO₃ per 1 mL into 75 L. The 2Hr Aquarist
This also lines up with the label chemistry (0.7% total N), which—depending on the liquid’s density—implies ~0.4–0.7 ppm NO₃ per 1 mL / 75 L. That’s because 0.7% N ≈ 7 mg N per mL (if ~1 g/mL), or a bit more if denser; converting N→NO₃ (×4.43) and spreading over 75 L lands in that ~0.4–0.7 ppm band.
Questions #2:
"so i started with about 1 ppm nitrate in my tank, did 70% water change, then added 2 ml of APT 3 immediately and then added 1 ml everyday on monday, tuesday, wednesday and today thursday. I tested nitrate today and it is 0.2 ppm. I want to know how much my tank is consuming also take into consideration nitrate generation from the tank fish/snail"
ChatGPT said:
Thought for 1m 7s
Got it—let’s back-solve your tank’s nitrate uptake from what you actually did.
Knowns (your timeline, 75 L tank)
- Start: 1.0 ppm NO₃
- 70% water change ⇒ 0.3 ppm remains
- Dose right after WC: 2 mL APT 3
- Then 1 mL/day on Mon, Tue, Wed, Thu (4 days total)
- Today’s test: 0.2 ppm NO₃
Step 1 — Total nitrate you added
- Immediate 2 mL: 2 × 0.65 = 1.30 ppm
- Daily 1 mL × 4 days: 4 × 0.65 = 2.60 ppm
Total dosed = 1.30 + 2.60 = 3.90 ppm
Step 2 — Net uptake per day
Let U = net NO₃ loss per day (plants + biofilter uptake minus any fish/snail NO₃ production).Final NO₃ after 4 days:
0.3⏟after WC+3.9⏟dosed−4U⏟4 days uptake=0.2⏟measured⇒4U=4.0⇒U≈1.0 ppm/day\underbrace{0.3}{\text{after WC}}+\underbrace{3.9}{\text{dosed}}-\underbrace{4U}{\text{4 days uptake}} = \underbrace{0.2}{\text{measured}}\Rightarrow 4U=4.0 \Rightarrow \boxed{U \approx 1.0\ \text{ppm/day}}after WC0.3+dosed3.9−4 days uptake4U=measured0.2⇒4U=4.0⇒U≈1.0 ppm/day
Net consumption ≈ 1.0 ppm NO₃ per day.
This already includes whatever nitrate your fish/snails are creating—i.e., your plants+bacteria are removing ~1.0 ppm/day after bioload is accounted for.
If you want gross plant uptake (separating fish/snail contribution)
Gross plant/bio uptake ≈ net uptake + bioload generation.Typical bioload generation in a moderately stocked, fed 75 L might be ~0.2–0.4 ppm/day (ballpark). That would put gross uptake around ~1.2–1.4 ppm/day. If your stock is very light/heavy, shift that number down/up accordingly.
