Living Soil Feeding Calculator

Living Soil Feeding Calculator

How much do I need?

Set your pot or bed size and get the exact amounts: charge, Veg and Bloom.

Soil volume
80 L
Grow length
Veg 4 weeks
Bloom 6 weeks
Build

Standard — the default. Full flavour, strong yield.

Phosphorus charge

Rock phosphate is the flavour-first charge — it adds phosphorus with no nitrogen, keeping the feed lean. Bone meal adds a little nitrogen (about 3.5%).

The charge, worked in once a week before planting (bone meal)
720 g
Veg blend
112 g / week
Over 4 weeks: 448 g
Bloom blend
107 g / week
Over 6 weeks: 640 g
Top-dress the Veg blend weekly through growth, switch to Bloom weekly once flowers set, then finish on plain water. Reusing last year's soil? Take a third of the charge (240 g) and keep the blends the same.
Max yield: also add ~0.6 g/L Amino Nitrogen Extract across two mid-flower doses.
Standard or Max yield?

Both builds use the same living-soil charge and the same Veg and Bloom blends — the only lever is nitrogen. Standard is our default: full flavour with a strong yield. Max yield runs a longer, roughly six-week veg and lifts nitrogen into the peak-weight window, at a little cost to flavour.

Max yield booster: on Max yield, also add our plant-based Amino Nitrogen Extract through mid-flower — about 0.6 g per litre of soil in total, split across two doses. It's the same fast amino-nitrogen already in the Veg and Bloom blends, simply topped up when the plant can use it.

Need more phosphorus or potassium?

Worked out for your 80 L of soil — both are optional add-ons for hungrier crops. The core charge, Veg and Bloom already cover most growing.

More phosphorus
240 g rock phosphate
≈ 3 g per litre, one-off with the charge
For root veg (carrots, parsnips, beetroot), transplants and phosphorus-poor soil. Micronised Rock Phosphate (31% P) — nitrogen-free, so it lifts phosphorus without pushing growth.
More potassium
20 g per bloom feed
≈ 0.25 g per litre each feed · 120 g over 6 bloom weeks
For heavy fruiters (tomatoes, peppers, potatoes, strawberries). Sulphate of Potash (50% K₂O), added through flowering.
Dr Forest · Made by Growers. Backed by Science.