High Intensity Discharge (HID) is one of the most efficient types of grow lighting that can be purchased. There are two types of HID, Metal Halide (MH) and High Pressure Sodium (HPS). These indoor grow lights are very safe. HID lighting systems are used in retail and groceries stores, gas stations, street lights and even in your back yard as a security light. Systems that are UL tested help assure safe lighting fixtures.
Metal Halide (MH) grow lights work better for vegetative growth and should be used as the primary light source for any plants. High Pressure Sodium (HPS) grow lights work best for fruiting and flowering plants. It works even better if you have another light source such as a window, greenhouse or sunroof.
There can be a number of reasons for this. Firstly, eliminate the obvious things like lack of water, high temperature or a broken stem. Root diseases are the most common cause of sudden death of plants and can cause many problems from loss of yield to complete collapse. Pythium is the most common disease, remedy: Applying DeFuse to your nutrients solution will eliminate any root diseases and many other fungal & bacterial problems.
This can be caused by too much fertiliser (too high EC), too much salt in the water, not enough water, or lights too close. Certain nutrient deficiencies can also cause leaf tip burn. Use a good nutrient and if in doubt change nutrient solution.
This can be caused by a number of factors: low oxygen levels due to lack of aeration or too much water, onset of root disease, pH is too high, the solution is too hot, too much salt in the water. All of these stop the plant from taking up nutrients in the correct quantities and balance, remedy: Use Go Green or Cal-Max to rectify the deficiency, just add to your nutrient solution.
Room temperature needs to be maintained at around 28 degrees in the vegetative phase and a couple of degrees lower in the flowering stage. It is better also to have dark period temperature lower than the light period temperature. 15-18 degrees during the dark period is okay in flowering stage.
Ventilation needs to be enough to maintain a temperature of about 28 degrees and a humidity of about 50% in the centre of the plant canopy. As a rule of thumb, during summer give about 120ltrs per second of air going in and the same amount being vented per square metre of floor area. Try to maintain the temperature inside no higher than outside. In winter, vent according to temperature and humidity, you will usually need less ventilation.
The time taken to strike roots on clones varies according to the time of the year and the health of the clones. About 5-12 days is usual. Use Rhizotonic or Roots Excelurator for a powerful root stimulant and keep the health of the plant in optimum form.
The best water will have low salts or contaminants. Rainwater is probably best though normal tap water is usually satisfactory and convenient as long as it is under 150ppm. The lower the ppm the better the results.