Mills Feeding Calculator
Estimate nutrient amounts for your reservoir using a practical Mills-style feed schedule. Enter your tank size, growth stage, and desired feed strength.
What this Mills nutrients calculator does
This page gives you a quick way to estimate how much Basis A, Basis B, Start-R, C4, Ultimate PK, and Vitalize to add to your water. Instead of doing the math by hand every time you mix a tank, the calculator converts your reservoir volume and feeding stage into exact milliliter amounts.
It is especially useful for growers who switch between tank sizes, run multiple systems, or adjust feed strength through the cycle. You can also account for water hardness and grow medium, which helps keep your feed program more consistent.
How the calculator works
1) Stage-based baseline rates
Each growth stage uses a baseline dosage in mL/L. Early stages are lighter, while mid-bloom has the highest overall demand.
2) Strength scaling
The strength slider applies a multiplier to all product rates. At 80% strength, every baseline value is multiplied by 0.80. This is useful for young plants, stressed plants, or genetics that feed lightly.
3) Water and medium adjustments
- Soft water: increases Basis A/B slightly to compensate for lower mineral content.
- Hard water: reduces Basis A/B slightly to avoid overloading calcium/magnesium-heavy water.
- Coco: increases C4 slightly to support high-frequency fertigations.
- Soil: decreases C4 slightly because nutrient release is buffered by the medium.
How to use it correctly
- Enter reservoir size (liters or gallons).
- Select your current plant stage.
- Set strength percentage.
- Pick water hardness and medium.
- Click Calculate Mix and follow the totals shown.
Always add nutrients one at a time to well-aerated water and mix thoroughly between additions.
Recommended mixing order
To reduce precipitation and keep solution stable:
- Start-R
- Basis A
- Basis B
- C4
- Ultimate PK
- Vitalize (last, very concentrated)
Practical feeding tips for better results
Monitor EC/PPM every feed day
The calculator gives dosage guidance, but your plants still decide what they can handle. Track EC in and EC runoff (or reservoir drift) to see if you should push up or back off.
Control pH after nutrients are mixed
Set pH only after all products are added. Typical targets:
- Hydro/coco: 5.7-6.2
- Soil: 6.2-6.7
Increase gradually, not suddenly
When plants look healthy, raise strength in small increments (5-10%). Large jumps often cause leaf tip burn, lockout, or unnecessary stress.
Common mistakes to avoid
- Mixing concentrates together before dilution in water.
- Running full strength on young plants too early.
- Ignoring source water EC.
- Using one schedule across all cultivars without adjustments.
- Skipping periodic flushes when salt buildup appears.
Important note
This calculator is an educational tool built from a practical Mills-style schedule, not an official manufacturer dosing chart. Always cross-check with current product labels and your own plant response, and adjust based on climate, lighting intensity, and cultivar behavior.