What is the recommended safe concentration of Urea (46-0-0) for a foliar spray application per liter of water?

For most crops, a safe foliar concentration is 5g to 10g of Urea (46-0-0) per 1 liter of water. Ensure application occurs during cooler morning or evening hours to prevent leaf burn. FertiCalc handles these dilution rates automatically.

A 0.5% to 1.0% solution is generally safe for most foliage, though testing on a small area is recommended.

Organic liquid urea alternatives may require slightly lower dilution ratios due to varying breakdown speeds compared to synthetic urea. Always refer to manufacturer specifications.

What is the mathematical formula for converting target Parts Per Million (PPM) into grams of fertilizer per liter of solution?

To convert PPM to Grams/L, use the formula: Grams/L = (Target PPM / (Fertilizer Nutrient Percentage / 100)) / 1000. Our professional calculator performs this conversion automatically for all 52+ supported fertilizers.

Keep in mind that tap water already contains baseline PPM (often 150-300 PPM). For high-precision hydroponic environments, you must subtract your starting water PPM from your target PPM before calculating the dry mass required.

Which NPK nutrient ratio is most effective for supporting plants during the flowering and bloom stages?

During the flowering stage, plants typically require higher Phosphorus (P) and Potassium (K) levels. A common effective ratio is 1:3:2 (e.g., 5-15-10), which supports reproductive growth and fruit development.

While 1:3:2 is a solid synthetic baseline, organic growers often use top-dressed bone meal and kelp extracts which release phosphorus and potassium more slowly over a 3-week period.

Are there any safety concerns or chemical compatibilities I should be aware of when mixing multiple fertilizers in a single concentrate?

Yes, but compatibility is critical. Never mix Calcium Nitrate with Magnesium Sulfate in the same concentrated stock solution as they will react to form insoluble Gypsum (precipitation). Always consult compatibility charts before mixing.

When mixing organic suspensions with synthetic salts, ensure you agitate the reservoir constantly. Organic particulates can act as nucleation sites, accelerating salt precipitation if left stagnant.

Fertilizer Database

Browse all 52+ fertilizers with complete NPK specifications

🌾 nitrogen

Name	Code	N %	Form	Action
Anhydrous Ammonia	82-0-0	82	💧 Liquid	Use
Aqua Ammonia	21-0-0	20.5	💧 Liquid	Use
Ammonium Nitrate	34-0-0	34	🪨 Granular	Use
Ammonium Nitrate Solution	20-0-0	20	💧 Liquid	Use
Ammonium Nitrate-Sulfate	30-0-0	30	🪨 Granular	Use
Ammonium Sulfate (AS)	21-0-0	21	🪨 Granular	Use
Ammonium Sulfate Solution	6-0-0	6	💧 Liquid	Use
Ammonium Sulfate-Urea	34-0-0	33.5	🪨 Granular	Use
Ammonium Thiosulfate	12-0-0	12	💧 Liquid	Use
Calcium Ammonium Nitrate	17-0-0	17	🪨 Granular	Use
Calcium Nitrate	15-0-0	15.5	🪨 Granular	Use
Calcium Nitrate-Urea	34-0-0	33.8	🪨 Granular	Use
Nitrogen Solution 28%	28-0-0	28	💧 Liquid	Use
Nitrogen Solution 32%	32-0-0	32	💧 Liquid	Use
Sodium Nitrate	16-0-0	16	🪨 Granular	Use
Sulfur Coated Urea (SCU)	36-0-0	36	🪨 Granular	Use
Urea	46-0-0	46	🪨 Granular	Use
Urea Solution	20-0-0	20	💧 Liquid	Use
Urea-Formaldehyde	38-0-0	38	🪨 Granular	Use
Blood, Dried	12-0-0	12	🪨 Granular	Use

🌱 phosphorus

Name	Code	N %	P₂O₅ %	Form	Action
Ammonium Metaphosphate	12-51-0	12	51	🪨 Granular	Use
Ammonium Phosphate	11-48-0	11	48	🪨 Granular	Use
Ammonium Polyphosphate	15-60-0	15	60	🪨 Granular	Use
Bone Meal, Raw	4-22-0	3.9	22	🪨 Granular	Use
Bone Meal, Steamed	2-27-0	2.2	27	🪨 Granular	Use
Calcium Metaphosphate	0-60-0	0	60	🪨 Granular	Use
Phosphoric Acid	0-54-0	0	54	💧 Liquid	Use
Single Superphosphate (SSP)	0-22-0	0	22	🪨 Granular	Use
Triple Superphosphate (TSP)	0-46-0	0	46	🪨 Granular	Use
Superphosphoric Acid	0-68-0	0	68	💧 Liquid	Use

💪 potassium

Name	Code	K₂O %	Form	Action
Potassium Carbonate	0-0-64	64	🪨 Granular	Use
Muriate of Potash (MOP)	0-0-60	60	🪨 Granular	Use
Potassium-Magnesium Sulfate	0-0-22	22	🪨 Granular	Use
Potassium Sulfate (SOP)	0-0-50	50	🪨 Granular	Use

🧬 compound

Name	Code	N %	P₂O₅ %	K₂O %	Form	Action
Diammonium Phosphate (DAP)	18-46-0	18	46	0	🪨 Granular	Use
Ammonium Phosphate Nitrate	27-14-0	27	14	0	🪨 Granular	Use
Ammonium Phosphate Sulfate	16-20-0	16	20	0	🪨 Granular	Use
Monoammonium Phosphate (MAP)	11-52-0	11	52	0	🪨 Granular	Use
Liquid Amm. Polyphosphate	10-34-0	10	34	0	💧 Liquid	Use
Potassium Metaphosphate	0-55-37	0	55	37	🪨 Granular	Use
Potassium Nitrate (KNO3)	14-0-44	14	0	44	🪨 Granular	Use
Potassium-Sodium Nitrate	15-0-14	15	0	14	🪨 Granular	Use
Castor Pomace	5-1-1	5	1	1	🪨 Granular	Use
Compost	2-2-1	2	2	1	🪨 Granular	Use
Cottonseed Meal	6-2-1	6.4	2	1	🪨 Granular	Use
Fish Scrap	6-6-6	6	6	6	🪨 Granular	Use
Guano	12-11-2	12	11	2	🪨 Granular	Use
Manure	1-1-1	0.5	0.5	0.5	🪨 Granular	Use
Sewage Sludge, Activated	6-2-2	6	2	2	🪨 Granular	Use
Soybean Meal	6-1-2	6	1	2	🪨 Granular	Use
Tankage, Animal	8-5-6	8.1	5.3	5.9	🪨 Granular	Use
Linseed Meal	6-2-1	5.6	2	1	🪨 Granular	Use

Showing 52 of 52 fertilizers