Compost Needed
8 cups
Brew
24 hr
Covers
250 sq ft
Additive
5 oz
5 oz
24 hr
250 sq ft
1
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Inputs
Result
5 gal × 0.10 ratio × 8.34 lbs/gal = 4.17 lbs. 4.17 / 0.5 lbs per cup = 8.34, rounds to 8 cups. Molasses = 5 × 1.0 oz/gal = 5.0 oz. Coverage = 5 / 0.02 = 250 sq ft.
Inputs
Result
3 × 0.08 × 8.34 = 2.0 lbs. 2.0 / 0.5 = 4 cups. Kelp = 3 × 0.25 = 0.75 oz. Coverage = 3 / 0.005 = 600 sq ft.
The standard compost-to-water ratio is 10% by weight for general aged compost — about 4.2 lbs (8 cups) of compost per 5 gallons of water. Worm castings use a lighter 8% ratio (3.3 lbs per 5 gallons), while fungal-dominant recipes use 12% for stronger inoculation.
| Compost Type | Ratio to Water | Brew Time |
|---|---|---|
| General Aged | 10% | 24 hours |
| Worm Castings | 8% | 18 hours |
| Fungal-Dominant | 12% | 36 hours |
| Bacterial-Dominant | 10% | 20 hours |
Most compost tea brews for 18–36 hours with active aeration. General compost tea is ready in 24 hours. Worm casting tea brews faster at 18 hours. Fungal-dominant tea needs 36 hours for fungal hyphae to develop. Do not brew longer than 48 hours — anaerobic bacteria take over and produce harmful compounds.
Unsulfured molasses is the most common additive at 1 oz per gallon — it feeds beneficial bacteria and accelerates multiplication. Fish hydrolysate (0.5 oz/gal) adds nitrogen and feeds fungi. Kelp meal (0.25 oz/gal) provides micronutrients and growth hormones. Humic acid (0.5 oz/gal) improves nutrient uptake.
For soil drenching, apply 0.02 gallons per sq ft — a 5-gallon batch covers 250 sq ft. For foliar spray (diluted 1:4 with water), 5 gallons of concentrate covers 1,000 sq ft. Apply every 2–4 weeks during the growing season for best results.
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Last Updated: Mar 20, 2026
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