Fertiliser Dosing Calculator
If you mix dry salts yourself, the grams you need depend on your tank volume and the scheme you follow. Enter the volume and get weekly and per-dose amounts.
EI — Estimative Index
Bilinçli olarak fazla besin verir; haftalık %50 su değişimi birikimi sıfırlar. Yüksek ışık ve CO2 olmadan alg üretir.
Tom Barr, Estimative Index (yüksek ışık, CO2 zorunlu)
EI — düşük ışık / haftalık
Düşük ışıklı, CO2 enjeksiyonu olmayan veya az olan düzenlemeler için.
Tom Barr, EI low-light varyantı
PPS-Pro
Günlük küçük dozlarla bitkinin tükettiği kadarını verir; su değişimi ihtiyacı düşüktür.
Edward Woo, Perpetual Preservation System Pro
PMDD
Fosfatı bilerek kısıtlar; alg kontrolünü PO4 sınırlamasıyla kurar. Modern bitkili akvaryumda tartışmalıdır.
Poor Man's Dosing Drops (Sears & Conlin)
Find the net water volume
Not gross volume — the water that actually goes in once substrate and hardscape are subtracted. In a typical planted tank that is 70-80 percent of the gross figure.
Pick the scheme that matches your light
EI assumes high light and injected CO2. In a low-light layout, EI doses grow algae rather than plants; use the low-light variant or PPS-Pro instead.
Keep macros and micros separate
Phosphate and iron precipitate in the same bottle. Dissolve KNO3 + KH2PO4 + K2SO4 together, keep iron in its own bottle and dose them on different days.
Ramp up gradually
Start at half the target dose and reach full dose over two weeks. Watch the plants and the algae; read the tank, not the table.
Do not skip water changes
EI works by over-supplying nutrients and resetting accumulation with a weekly water change. Skip the change and the scheme loses its own premise.
What is EI dosing?
The Estimative Index is Tom Barr's dosing approach. It supplies more nutrients than plants consume and resets accumulation with a weekly 50 percent water change, so nothing becomes limiting and routine testing is unnecessary. It assumes high light and injected CO2.
Which scheme should I use?
Light intensity decides. With high light and CO2, use EI; in a low-light or CO2-free layout, use the EI low-light variant; if you prefer small daily doses and minimal water changes, PPS-Pro fits. PMDD deliberately limits phosphate and is contested in modern planted-tank practice.
KNO3 already contains potassium — do I still need K2SO4?
This calculator meets the nitrate target with KNO3 and the phosphate target with KH2PO4 first; both carry potassium. Only the remaining potassium deficit is then filled with K2SO4. Skipping that order overshoots the potassium target substantially — a common mistake in hobby calculators.
Can I mix macros and micros in one bottle?
No. Phosphate and iron form iron phosphate and precipitate out, so the iron never reaches the plants. Prepare macros (KNO3, KH2PO4, K2SO4) in one bottle and iron in another, and dose them on different days.
Do I always need to add magnesium?
It depends on your tap water. If it already carries more than 5 mg/L of magnesium, no addition is needed. On soft or RO water you should add Epsom salt; magnesium deficiency shows as interveinal yellowing on older leaves.
Why do these amounts differ from another chart?
Usually for one of two reasons. Volume: net water volume must be used, not gross. Units: some sources express potassium as K2O and nutrients as elemental N and P, whereas this calculator uses what test kits actually measure — NO3 and PO4 as ions, K and Mg as elements.