Doseer Calculator
🌱 Beginner 🔬 Expert
🌿 Plants
NL EN ⚠ Disclaimer
Volume: 330 L CO₂: 10:00 Lights: 12:30–20:30 Chihiros WRGB2 Pro TDS: 120 ppm Products: 6
🌱
Getting started — 4 simple steps
① Enter your tank size ② Choose your soil ③ Select products ④ Click Calculate
Switch to Expert for CO₂, PAR, RGBW and water analysis → Expert mode →
📐 Volume calculator
Soil layer thickness (front and back can differ — Dutch style slopes)
Enter dimensions above to calculate volume.
Timing settings
Daily timeline
night
CO₂
dosing
light 8h
CO₂↓
night
00:0003:0006:0009:00 12:0015:0018:0021:0024:00
10:00CO₂ on150 min before lights
12:15Dose fertilizers15 min before lights
12:30Lights on480 min light period
19:30CO₂ off60 min before lights off
20:30Lights off
Product selection
Recommended starter package 🌿
For a Dutch style tank with CO₂, the most common choice is:
Masterline Red + Lean (micros, alternating) · Phosphate + Potassium (macros) · Iron + Carbo (always recommended)
Not sure? Leave the default selection — it is already the recommended Dutch style setup.
🌿 All-in-one
🔬 Micro + color
⚗️ Individual macros
⭐ Always recommended
💧 Water treatment
🌱 Substrate & roots
💡 Product advice
Red (mon/wed/fri) + Lean (tue/thu/sun) — classic Dutch style combination. Maximum color and balanced micros.
Masterline Iron (DTPA) — does not react with PO₄ and ensures stable Fe levels.
Masterline Carbo alongside CO₂ — mild algae-inhibiting effect during light period.
PO₄ + K separately — maximum control per element.
Selected products
Iron Carbo Red Lean Phosphate Potassium
Red + Lean alternating per day is the recommended combination.
Lean + Red alternating per day is the recommended method.
Daily dosing time
12:15
15 min before lights on
CO₂ already 135 min active
Lights on at 12:30
Settings overview
🌱 Soil Age unknown
APT Feast Soil
🫧 CO₂ 10:00 → 19:30
On: 10:00  ·  Off: 19:30  ·  Dose: 12:15
150 min before lights · 480 min light period
✓ CO₂ timing looks good.
💡 Lighting 70 µmol
Chihiros WRGB2 Pro
Depth: 50cm · PAR @50cm: 70 µmol/m²/s
R 85% G 60% B 85% W 40% ★ 100/100
R
G
B
W
💡 PAR is on the low side. Suitable for low-demand plants only.
💧 Water 120 ppm
RO water
TDS: 120 ppm ·
CO₂ targets & bubble guide
Drop checker color
Blue — too little CO₂ — <15 mg/L
Yellow-green — ideal (28–35)
Yellow — too much (>40 mg/L)
Bubbles per second (general guideline, depends on diffuser)
1–2 bps
Up to 100L
2–4 bps
100–200L
4–7 bps
200–350L
6–10 bps
350L+
PPM CO₂ measurement vs KH & pH
Estimate CO₂ with KH × 3 (pH based) — use a proper CO₂ test for accuracy.
pH KH 1° KH 2° KH 3°
6.035 ✓70105
6.222 ✓44 ✓66
6.414 ✓28 ✓42 ✓
6.6918 ✓27 ✓
6.861122 ✓
7.04812
✓ = In ideal Dutch style range (20–45 mg/L)
Target: CO₂ 25–35 mg/L · pH 6.4–6.7 · KH ~1°dKH
Check: Green drop checker stable throughout entire light period.
Lighting — PAR & RGBW settings
Estimated PAR at substrate
70 µmol/m²/s
050100150200250+
Ideal for Dutch style with CO₂
Dutch style target: 80–150 µmol/m²/s
Your light settings
85%
60%
85%
40%
Defaults from lamp database. Enter your actual values for a personalised Dutch style score. Pro models support overdrive (> 100%).
Light analysis
100
Dutch style score
Excellent
R ≥ 75% — excellent for red pigmentation in Rotala, Ludwigia and Alternanthera.
G 60% — good green balance.
B 85% — good blue component for compact plant growth.
W 40% — subtle white, good for Dutch style color rendition.
Lamp info
BrandChihiros
ModelWRGB2 Pro
ChannelsRGBW
AppChihiros App
Tips for this light
Increase R for red plants. Keep B higher than G to reduce algae. Keep W low.
Powerful light. Start at 50% and increase 5% weekly. For Dutch style: ramp 30 min.
Build-up schedule:
  • → Week 1–2: 50% intensity
  • → Week 3–4: +5% per week
  • → Month 2+: increase to target settings
Substrate — soil type & age
Substrate (soil)
Long-lasting soil from STRAAT Dutch Style. Focused on macronutrient release. Buffers pH 6–6.8. Stable release up to 12–18 months. Less PO₄ absorption than ADA.
Water type & TDS — quality & product advice
💧 Water type
Select your water type and enter the TDS value (measured with a TDS meter, or use 120 ppm for RO water as a good starting point).
TDS scale for planted aquariums
120
0 50 150 280 450 550+
Very soft Soft ✓ Dutch Medium Hard Very hard
Soft (Dutch style ideal)
120 ppm  RO / Osmosis water
Perfect range for Dutch style aquariums. Optimal CO₂ availability, good plant nutrient uptake. All stem plants thrive here.
Suitable plants: All Dutch style plants · Rotala sp., Ludwigia sp., Samolus, Alternanthera
Recommended Masterline products
Masterline GH Plus
Raises GH · remineralisation RO water
Dosage advice:
With RO water: add GH Plus to TDS ~120 µS/cm. Maintain KH ~1°dKH.
Water type advice
💧 RO / Osmosis water
  • → Always remineralize with Masterline GH Plus
  • → Target GH 3–5°dGH before adding to tank
  • → Adjust KH with small amount of NaHCO₃ (≈1°dKH)
  • → No chlorine = no Safe Water needed
  • → Best choice for Dutch style — full control
Dutch Style water targets
TDS
80–150 ppm
KH
1–2 °dKH
GH
3–5 °dGH
pH
6.4–6.8
TDS ranges per plant category
Plant type TDS (ppm) KH Examples Masterline product
🔵 Very demanding soft-water 0–80 ppm 0–1°dKH Tonina sp., Eriocaulon, Utricularia GH Plus (minimal) + NaHCO₃
🟢 Dutch style stem plants 80–150 ppm 1–2°dKH Rotala sp., Ludwigia sp., Alternanthera, Samolus GH Plus + KH Minus if needed
🟢 Carpeting plants 80–150 ppm 1–2°dKH HC Cuba, Eleocharis, Staurogyne GH Plus (RO water)
🟡 Easy stem plants 120–250 ppm 2–4°dKH Hygrophila, Bacopa, Limnophila Safe Water (tap) or GH Plus (RO)
🟡 Rosette plants / Crypts 100–300 ppm 2–5°dKH Cryptocoryne, Echinodorus, Sagittaria Safe Water or GH Plus
🔴 Hard water plants 250–500 ppm 4–8°dKH Vallisneria, Cabomba, Hornwort Safe Water only
Highlighted row = your current TDS range
GH Plus — remineralisation calculator
Pure RO water ≈ 0°dGH
✓ Dutch style range
= water change volume (99–132 L)
You need
13.2
gram
That is
4.4
measuring spoons (≈3g)
GH rise
4.0
°dGH
How to use:
Dissolve 13.2g of GH Plus in a bucket with your 99L of fresh RO water. Stir well until fully dissolved, then add to the aquarium. Test GH with a test kit after mixing.
📊 TDS guide — measuring with a TDS meter Approximation
Important: TDS and GH are not the same. TDS measures all dissolved ions (including fertilizers, KH, and more). GH measures only Ca²⁺ and Mg²⁺. The values below are valid only for Masterline GH Plus in pure RO water, before adding other products. Practical value: ~22 ppm TDS per °dGH.
🔢 Forward: GH target → expected TDS
Expected TDS after GH Plus
88
ppm / µS
Dutch style target: 80–150 ppm ✓
🔄 Reverse: measured TDS → approx. GH
Estimated GH (approx.)
0
°dGH
⚠ Use a GH test kit for accurate measurement
Reference table — Masterline GH Plus in RO water (~22 ppm TDS per °dGH)
GH TDS (ppm) Status For
1°dGH 22 ⚠ Very soft — Tonina, Eriocaulon, shrimp
2°dGH 44 ⚠ Soft — demanding Dutch plants
3°dGH 66 ✓ ✓ Dutch style minimum
4°dGH 88 ✓ ✓ Dutch style ideal — Rotala, Ludwigia
5°dGH 110 ✓ ✓ Dutch style ideal — all stem plants
6°dGH 132 💡 Slightly above Dutch style — still good
8°dGH 176 💡 Above ideal — reduce with more RO water
⚠ These TDS values apply only to pure RO water + Masterline GH Plus. Adding fertilizers or NaHCO₃ will increase TDS further.
Formula: 1 measuring spoon (≈3g) per 15L raises GH by 6°dGH. Source: Masterline product specification.
Weekly schedule — dosing per day
💡 How to read this: Each column is one day of the week. The coloured pills show which fertilizer to add and how much. Saturday = rest day (no dosing). Sunday = water change day.
Mon
Tue
Wed
Thu
Fri
Sat
Sun
12:15
Iron 3.0ml Carbo 11.0ml Red 11.0ml Phosphate 7.0ml Potassium 4.0ml
Iron 3.0ml Carbo 11.0ml Lean 11.0ml Phosphate 7.0ml Potassium 4.0ml
Iron 3.0ml Carbo 11.0ml Red 11.0ml Phosphate 7.0ml Potassium 4.0ml
Iron 3.0ml Carbo 11.0ml Lean 11.0ml Phosphate 7.0ml Potassium 4.0ml
Iron 3.0ml Carbo 11.0ml Red 11.0ml Phosphate 7.0ml Potassium 4.0ml
REST
↺ 99–132L water change Iron 3.0ml Carbo 11.0ml Lean 11.0ml Phosphate 7.0ml Potassium 4.0ml
★ K extra on change day = replenishment after water change  ·  Saturday: no dosing  ·  Today: Tue
Dosing pump — channel assignment
PumpChannelFertilizer TimeDaily vol.Weekly vol.Bottle
4-channelK1Masterline Iron
DTPA chelated Fe · no PO₄ reaction
12:153.0ml18.0 ml1000ml → ~55.6 weeks
4-channelK2Masterline Carbo
Algae inhibitor · effective during light period
12:1511.0ml66.0 ml500ml → ~7.6 weeks
4-channelK3Masterline Red
Elevated Fe · mon/wed/fri · red plants
12:1511.0ml33.0 ml500ml → ~15.2 weeks
4-channelK4Masterline Lean
Balanced micros · tue/thu/sun
12:1511.0ml33.0 ml500ml → ~15.2 weeks
2-channelK5Masterline Phosphate
+0.5 ppm PO₄ per 11ml/30L
12:157.0ml42.0 ml1000ml → ~23.8 weeks
2-channelK6Masterline Potassium
+1.0 ppm K per 11ml · extra Sunday
12:154.0ml (sun: 15.0ml)24.0 ml1000ml → ~41.7 weeks
Weekly usage & bottle duration
Iron
18.0 ml
per day: 3.0ml
Mon, Tue, Wed, Thu, Fri, Sun
bottle 1000ml → ~55.6 weeks
Sizes: 500ml · 1000ml ✓
Carbo
66.0 ml
per day: 11.0ml
Mon, Tue, Wed, Thu, Fri, Sun
bottle 500ml → ~7.6 weeks
Sizes: 200ml · 500ml ✓ · 1000ml · 5000ml
Red
33.0 ml
per day: 11.0ml
Mon, Wed, Fri
bottle 500ml → ~15.2 weeks
Sizes: 200ml · 500ml ✓ · 1000ml · 5000ml
Lean
33.0 ml
per day: 11.0ml
Tue, Thu, Sun
bottle 500ml → ~15.2 weeks
Sizes: 200ml · 500ml ✓ · 1000ml · 5000ml
Phosphate
42.0 ml
per day: 7.0ml
Mon, Tue, Wed, Thu, Fri, Sun
bottle 1000ml → ~23.8 weeks
Sizes: 500ml · 1000ml ✓ · 5000ml
Potassium
24.0 ml
per day: 4.0ml · sun: 15.0ml
Mon, Tue, Wed, Thu, Fri, Sun
bottle 1000ml → ~41.7 weeks
Sizes: 500ml · 1000ml ✓ · 5000ml
Nutrient Accumulation — 14-day model
High-tech CO₂ tank: 60–80%
Dutch style: 30–40%
Model:
Daily concentration = previous day × (1 − uptake/7) + dose if dosing day. Water change removes 35%.
Enter values and press Enter or click Recalculate.
PO₄
Target: 0.05 – 0.5 ppm
↓ Below target After 14 days: 0.008 ppm
0.00
0.00
0.00
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
Mo
Tu
We
Th
Fr
Sa
Su
Mo
Tu
We
Th
Fr
Sa
Su
Week 1
Week 2
Water change day (35%)
Saturday (rest)
✓ Target range: 0.05–0.5 ppm
K
Target: 10 – 30 ppm
↓ Below target After 14 days: 0.004 ppm
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.01
0.01
0.01
0.00
Mo
Tu
We
Th
Fr
Sa
Su
Mo
Tu
We
Th
Fr
Sa
Su
Week 1
Week 2
Water change day (35%)
Saturday (rest)
✓ Target range: 10–30 ppm
Fe
Target: 0.05 – 0.3 ppm
↓ Below target After 14 days: 0.002 ppm
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Mo
Tu
We
Th
Fr
Sa
Su
Mo
Tu
We
Th
Fr
Sa
Su
Week 1
Week 2
Water change day (35%)
Saturday (rest)
✓ Target range: 0.05–0.3 ppm
Summary
PO₄ is very low after 14 days (0.008 ppm). Consider increasing the daily dose or adding more dosing days.
K is very low after 14 days (0.004 ppm). Consider increasing the daily dose or adding more dosing days.
Fe is very low after 14 days (0.002 ppm). Consider increasing the daily dose or adding more dosing days.
⚠ This model uses approximate Masterline product concentrations (mg/ml) and a simplified plant uptake formula. It gives a directional indication, not an exact measurement. Always verify with test kits (PO₄, Fe, NO₃).
Guidelines

CO₂ & lighting

  • CO₂ on at 10:00 — 150 min before lights
  • Dosing at 12:15 — 15 min before lights
  • Lights on at 12:30
  • CO₂ off at 19:30 — 60 min before lights off
  • Lights off at 20:30 — 8 hours light
  • Drop checker green during full light period

Product usage

  • Masterline Iron and PO₄ may be dosed simultaneously — DTPA does not bind in tank
  • Never mix products concentrated in one bottle
  • Red/Lean alternate per day — not both on same day
  • Saturday: no dosing
  • Sunday: first change, then immediately dose
  • UV filter: off during dosing

Water change (Sun)

  • Change 99–132L (30–40%) RO water
  • Remineralize to TDS 100–120 µS/cm
  • Adjust KH to ~1 °dKH with NaHCO₃
  • Dose all fertilizers immediately after change
  • Potassium 15.0ml on Sunday (replenishment)
  • Test PO₄ before/after change

Troubleshooting

  • GSA on glass → increase PO₄
  • Pale new leaves → increase Iron
  • Pinholes in leaves → increase Potassium
  • Twisted new leaves → test Calcium
  • Red plants fading → dose Red more often or increase Iron
  • Always adjust one variable at a time
Algae — types, causes & solutions
Algae type Cause Solution
Green Spot Algae (GSA) PO₄ deficiency, too much light, low CO₂ Increase Masterline Phosphate · reduce light · improve CO₂
Green Dust Algae (GDA) High NO₃, new unstable tank, fluctuating parameters Let glass algae run its course (3–4 weeks), limit cleaning · stabilize water parameters
Black Beard Algae (BBA) CO₂ fluctuations, low or unstable CO₂ flow Stabilize CO₂ injection · check diffuser · dose Carbo directly on affected areas · improve flow
Hair / Thread Algae High light, low CO₂ or nutrients, new tank Improve CO₂ · balance nutrients · add Amano shrimp · check flow
Staghorn Algae CO₂ fluctuations (often at end of light period), low flow Check CO₂ timing · increase flow · direct Carbo treatment · remove manually
Cyanobacteria (BGA) Low NO₃, stagnant flow, new substrate, insufficient light Increase NO₃ (add Nitrate) · improve flow · blackout 3 days · clean substrate
Green Water Ammonia spike, new tank, high nutrients, low plant mass UV filter (daytime) · 50% water change · reduce light · add fast-growing plants
Diatoms (Brown Algae) New tank silicate phase, low light, low CO₂ Wait (usually disappears after 4–8 weeks) · Nerite snails · increase light/CO₂
Fuzz Algae (short green) Low CO₂, excess light, low plant competition Optimize CO₂ · reduce light time to 6–7h · add Amano shrimp
Substrate nutrition — soil status & recommendations
APT Feast Soil
Long-lasting soil from STRAAT Dutch Style. Focused on macronutrient release. Buffers pH 6–6.8. Stable release up to 12–18 months. Less PO₄ absorption than ADA.
0
months old
0–6m
Active
6–13m
Stable
13–20m
Declining
20m+
Depleted
Root Caps
Solid capsules pressed near roots. Slowly release macros for weeks.
  • → Soil 6+ months old
  • → Every 1–2 months
  • → Large rooting plants
Sizes: 60 pcs · 125 pcs
Root Max
Liquid root stimulator for freshly planted stems.
  • → When planting new stems
  • → After replanting
  • → First 2–4 weeks startup
Sizes: 100ml · 250ml · 500ml
Recommended approach
0–6 months:
Root Max at planting · soil provides rest

6–12 months:
Root Caps at large plants · Root Max at replant

12+ months:
Root Caps every 6–8 weeks · consider partial soil replacement