The ideal PPFD level for seedlings is between 100-300 micromoles per square meter per second (μmol/m²/s). This softer lighting mimics the diffused sunlight of early spring, providing enough energy for seedling-stage plants to develop their initial leaves without overwhelming them. at 48 inches from light sources, the seedlings receive around 150-180μmol/m²/s, as they grow they grow towards the higher levels of ppfd naturally. Urine is a liquid waste product as a result of our kidneys cleaning and filtering our blood. Typically, urine contains around 95% water and the rest are a mix of salts including sodium, potassium and chloride, urea, and uric acid. Due to the high water content in pee, the more you drink, the more you have to go. For a healthy person, human urine typically has a pH of around 6.2 with a range of 5.5-7.0. A person’s diet and alcohol consumption can also affect the pH of their urine. The main organic component of urine is urea, a combination of ammonia and carbon dioxide, which is the byproduct of our bodies breaking down proteins into usable amino acids. Urea is very high in nitrogen, a key ingredient to healthy leafy growth in plants. In addition to being very nitrogen-rich, urine also contains dissolved phosphorus that’s immediately available to plants, making urine a quick-acting fertilizer. If you own a dog, you may be familiar with yellow patches on your lawn where your pet has peed. Dogs and cats excrete fresh urine with a higher quantity of urea than humans do and that can more easily burn a plant upon contact. Human urine contains less urea and thus less ammonia. Despite Bear Grylls drinking urine in his popular survival shows, urine is not sterile. It picks up trace amounts of bacteria as the sterile version passes through the bladder, the urinary tract and comes in contact with the skin. Still, the health risks of using urine are very low because urine does not typically contain pathogens found in feces. Infectious diseases like cholera are spread through water sources contaminated by poop. In areas with poor sanitation, there is no way to separate solid and liquid waste which is why all untreated mixed sewage can pose significant public health risks. Only 10-15% of all nutrition you ingest is absorbed, all the rest is disposed of in the urea of urine, 95% Water, 5% Urea. Human urine consists primarily of water (91% to 96%), with organic solutes including urea, creatinine, uric acid, and trace amounts of enzymes, carbohydrates, hormones, fatty acids, pigments, and mucins, and inorganic ions such as sodium (Na+), potassium (K+), chloride (Cl-), magnesium (Mg2+), calcium (Ca2+), ammonium (NH4+), sulfates (SO42-), and phosphates (e.g., PO43-).1 A Representative Chemical Composition of Urine Water (H2O): 95% Urea (H2NCONH2): 9.3 g/l to 23.3 g/l Chloride (Cl-): 1.87 g/l to 8.4 g/l Sodium (Na+): 1.17 g/l to 4.39 g/l Potassium (K+): 0.750 g/l to 2.61 g/l Creatinine (C4H7N3O): 0.670 g/l to 2.15 g/l Inorganic sulfur (S): 0.163 to 1.80 g/l The pH of human urine ranges from 5.5 to 7, averaging around 6.2. The specific gravity ranges from 1.003 to 1.035. Significant deviations in pH3 Chemical Concentration in g/100 ml urine Water 95 Urea 2 Sodium 0.6 Chloride 0.6 Sulfate 0.18 Potassium 0.15 Phosphate 0.12 Creatinine 0.1 Ammonia 0.05 Uric acid 0.03 Calcium 0.015 Magnesium 0.01 The element abundance depends on diet, health, and hydration level, but human urine consists of approximately: Oxygen (O): 8.25 g/l Nitrogen (N): 8/12 g/l Carbon (C): 6.87 g/l Hydrogen (H): 1.51 g/l Morning piss is best, diluted to 6-10 parts water. Breaking Down Nitrogen Forms & Their Impact: Forms of Nitrogen: Nitrogen, comes in three primary forms: ammonium, nitrate, and urea. Ammonium (NH4+) carries a positive charge, nitrate (NH3–)carries a negative charge, while urea ((NH2)2CO) carries no charge. Natural Processes in Media: Once these nitrogen forms are introduced into the growing media, natural processes kick in. Bacteria play a vital role, converting urea to ammonium or ammonium to nitrate. This latter conversion releases hydrogen ions, increasing media acidity. Urea Conversion: Urea undergoes rapid conversion to ammonium in the soil, usually within two days. Both urea and ammonium are often grouped together and referred to as ammoniacal nitrogen. When plants absorb nitrogen, they typically release a molecule with the same charge to maintain internal pH. This process can also alter the pH of the media surrounding the roots. pH Effects of Nitrogen Uptake: Ammonium (NO4) Uptake and pH: When plants absorb ammonium, they release hydrogen ions (H+) into the media. This increases the acidity of the media over time, decreasing the pH. Nitrate (NO3) Uptake and pH: Plants take up nitrate by releasing hydroxide ions (OH–). These ions combine with hydrogen ions to form water. The reduction in hydrogen ions eventually reduces the media acidity increasing the pH. Nitrate (NO3) Absorption Variations: Sometimes, plants absorb nitrate differently, either by taking in hydrogen ions or releasing bicarbonate. Like hydroxide ions, bicarbonate reacts with hydrogen ions and indirectly raises the media pH. Understanding these processes helps in choosing the appropriate fertilizer to manage media pH. Depending on the nutrients present, the media’s acidity or alkalinity can be adjusted to optimize plant growth. Risks of Ammoniacal Nitrogen: Plants can only absorb a certain amount of nitrogen at a time. However, they have the ability to store excess nitrogen for later use if needed. Nitrate (NO3) vs. Ammonium (NH4): Plants can safely store nitrate, but too much ammonium can harm cells. Thankfully, bacteria in the media convert urea and ammonium to nitrate, reducing the risk of ammonium buildup. Factors Affecting Ammonium (NH4) Levels: Certain conditions like low temperatures, waterlogged media, and low pH can prevent bacteria from converting ammonium. This can lead to toxic levels of ammonium in the media, causing damage to plant cells. Symptoms of Ammonium (NH4) Toxicity: Upward or downward curling of lower leaves depending on plant species; and yellowing between the veins of older leaves which can progress to cell death. Preventing Ammonium (NH4) Toxicity: When it comes to nitrogen breakdown of a nutrient solution, it’s crucial not to exceed 30% of the total nitrogen as ammoniacal nitrogen. Higher levels can lead to toxicity, severe damage, and even plant death. Ideal Nitrogen Ratio for Cannabis: Best Nitrogen (NO3) Ratio: Research shows that medical cannabis plants respond best to nitrogen supplied in the form of nitrate (NO3). This helps them produce more flowers and maintain healthy levels of secondary compounds. Safe Ammonium (NH4) Levels: While high levels of ammonium (NH4) can be harmful to cannabis plants, moderate levels (around 10-30% of the total nitrogen) are are considered most suitable. This level helps prevent leaf burn and pH changes in the media. Nitrogen: nitrate (NO3-) and ammonium (NH4+) Nitrogen is mobile in the plant. When it is in the soil it is mobile as Nitrate NO3– and is immobile as Ammonium NH4+ All those nutrients should be in ionic form, either in the soil or in a nutrient solution. Ions are simply the atomic or molecule form having +ve or –ve charge. As we know, the positive attracts the negative, and the same charge elements will repel each other; this power of charge represents the strength of the element. The positive ions are known as Cation, while negative ions are Anions. The anions want to disperse themselves to even concentrations, so they move from higher concentrations to lower concentrations. As we look at the soil structure, it’s a composition of particles; those particles attract the positive ions (+Ve), repel the Negative ions (-ve), and float freely in the water. This attraction of Cation by the soil particles is called Cation Exchange Capacity (CEC), which measures the number of cations that can be retained by the soil particles. The higher the CEC, the more Cation Nutrients can be stored in the soil. As a result, the higher CEC soils can become more nutrient-rich; also, keep in mind the soil composition is diverse and varies among different soil types.