Leaves are drooping/wilting?
This could be a number of problems. If the temperature is too high, leaves will wilt and the edges may curl upwards as well. Raise the lights away from the plant canopy or use something to cool the bulbs, like our Air Cooled Lighting range.
If the leaf appears limp and lifeless, it suggests underwatering. If the leaf is firm but droops at the stem, is suggests overwatering. For both scenarios, use a soil moisture metre to check that you are giving the right amount to your plants.
Lack of oxygen in the nutrient solution could also cause drooping/wilting. Water holds less oxygen when warm, so keep temperatures between 18-22°C with a water chiller/heater and use an air stone or air pumps to increase oxygen.
Leaves are yellowing between the veins?
This could be a sign of magnesium deficiency, most common during early flower stage. Magnesium deficiency can occur as a result of the pH being too low, when calcium is lacking or when a strong PK additive has been used. Check the pH, raise to above 6.5 in soil and 5.8 in hydroponics. If there is no change after a couple of days, Epsom salts or supplements such as the Shogun Fertilisers Calmag can be applied.
Leaves turning a pale green or yellow?
Nitrogen deficiencies often appear in older leaves first, and can cause your leaves to turn a pale green, or yellow. You may see stunted growth and spindly stems. To treat nitrogen deficiency, the simplest way is to increase the dosage the grow fertiliser. Start by increasing the grow feed by 1ml per litre of water until the plants leaves are started to come through lush and green again. If nitrogen levels are really low, a supplement such as House & Garden N 27% Nitrogen can be used to give a boost.
Read our blog: How To Identify & Treat Nitrogen Deficiencies
Leaves smaller than usual with a blue/green tint and dark blotches appearing?
This could be a sign of a phosphorous deficiency, most commonly happening due to the pH being outside the recommended zone. Lower pH to 5.5-6.2 in hydro and 5.5-6.5 in soil. Feed with base nutrients or add supplementary phosphorous.
Yellowing leaves with rust blotches and burnt edges?
This could be a potassium deficiency. Although plants appear vigorous and tall, branches are weak and the leaves are dull. Feed plant with base nutrients or add supplementary potassium, such as Canna Minerals K 20%.
How do I control pests?
Thoroughly cleanse the area before putting the plants in, make sure your intake fan has either a carbon filter attached, and air sock or a tight mesh covering the opening and ideally wear a pair of overalls to ensure any pests that may come in contact with your clothing aren’t transferred into your grow room.
Read our blog: How to prevent pests
Finding yellow-white spots on the leaves?
This could be a sign of a spider mite infestation. Check for tiny moving specks on the underside of the leaves, and fine webs between branches. Decrease temperature and raise humidity to slow their life cycle. Remove any leaves with more than 50% of damage and use pesticides, smoke bombs or predators.
Silvery white specks found on the top of leaves?
Damage can look similar to that of spider mites, but without the webbing. Shake the plant to find any Thrips hiding under the leaves. These are difficult to control with sprays as they are often resistant to pesticides and hide in the soil. It is recommended to use Thrips predators.
Roots turning brown and slimy?
Pythium (root rot) is a fungal infection that thrives in warm, oxygen-poor water and soggy soil. Prevent it by using beneficial microbes such as Viresco, change the nutrient tank weekly and be sure to sterilise all equipment at the beginning of a grow. If infected, reduce water temperature to 18-22°C, increase oxygenation and use cleaning agents such as Root Rot Stop or Pythoff.