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Beginners Guide to Hydroponics

How long should I run my lights ?

Vegetative phase = 18 hrs per day.

Flowering phase = 12 hrs per day.

What distance between light and plant is best?

The gap should be approx 40cm for 400W, 40-60cm for 600W and 60cm for 1000W globes.

Also a fan blowing gently between the plant and globe will help with heat building up.

If using “cool tubes” then lights may be run much closer!

What is the best light to use, High Pressure Sodium (HPS) or Metal Halide (MH)?

In our trials, we found that HPS (versus MH), when used for an entire crop cycle, slightly but noticeably out performed MH. We have also found that HPS gives a marginally better yield if it used for the bloom phase and the

MH performs slightly better during the growth phase. For best results use an MH for growth and an HPS for the flower phase.

How often should I change my globes?

For best results change your globes about every 3000 hours. We have calculated a 10% loss between 3000-4000 hours and a 25% loss from 4000 hours of usage. A light meter is also a useful tool for measuring the loss of your globes.

Do I need reflective material on the walls? E.g. Mylar.

You don’t need Mylar on the walls but reflective walls mean more light which means more growth and extra yield.

What temperature should the growing room be?

Daytime 26 -28 °C

Nighttime 20 – 23°C

Use a thermometer to record temps/swings. A thermostat is also a useful tool for controlling temps.

What humidity should I maintain?

50-60% is ideal.

How much ventilation is necessary?

Ventilation needs to be enough to maintain a temperature of about 26-28°C and a humidity of about 50% in the centre of the plant canopy. Generally it is better to have too much than too little ventilation to raise co2 levels for your plants. Use a thermo/hygrometer to record humidity swings. A fan is a useful tool to remove humidity. A dehumidifier may help in humid conditions or in co2 grow rooms.

What brand of nutrients should I use?

At Glandore Hydroponics, every brand we sell is of the highest quality. Our personal opinion is Dutch brands as they seem to work better than locally made brands – Try House & Garden or Canna nutrients.

What PPM – EC should I maintain?

This changes with the growth phase and time of year.

It is also different for each brand of nutrient. A truncheon or a simple EC pen will be suitable to measure. If too weak- add more nutrient. If too strong- add water.

A General Guide for media such as Perlite and Expanded Clay Balls.

Vegetative: 840 PPM – 1540 PPM | 1.2-2.2 EC

Flowering: 1260 PPM – 1680 PPM | 1.8- 2.4 EC

A General Guide for media such as Coconut Fibre

Vegetative: 840 PPM – 1400 PPM | 1.2-2.0 EC

Flowering: 1260 PPM – 1540 PPM | 1.8- 2.2 EC

What pH should I maintain?

6.0 – 6.6 Recirculation

5.5 – 5.8 Run To Waste

A pH pen or Ecoscan2 or even a simple test kit can be used to check pH. You will also need pH(up) and pH(down) to correct the pH of the solution.

The last three weeks of Flower, Run Your pH at 6.2 – 6.8.  This willmake P/K more available to the plants.

Products like H&G shooting powder and Canna PK/13/14 work much better.  

What is the different between a recirculating system and a run to waste system (RTW)?  

A recirculating system is one where the nutrient solution is continuously pumped from a reservoir to the plant and then drains back to the reservoir.

The same water is used over and over though the reservoir is occasionally refilled to replace the water used by the plant. An RTW system is where the nutrient solution is pumped from the reservoir to the plant then discarded.

Growing in coco is an example of RTW.

How often should I water in Perlite?

The amount of irrigation water to apply is perhaps more important than how and when to irrigate.

A general rule of thumb to follow in irrigating plants is to apply 10-15% more water than the container will hold. Frequency of application will depend upon plant size and grow room temperature, but will vary from once or twice daily immediately after transplanting to several times per day on warm days during harvest. Only water the plants during the day period.

How often should I water in Clay Balls?

A general rule of thumb to follow in irrigating plants is to apply 10-15% more water than the container will hold. Frequency of application will depend upon plant size and grow room temperature, but will vary from one 15 minute feed every hour while the lights are on during the first weeks of growth then one 15 minute feed every two hours starting several minutes before the lamps have been turned on. Only water the plants in the day period.

How often should I water in Coco Fibre?  

If you are using a pot over 30Ltr water once per 24 hours until the plant reaches 30cm wide/high, Then 2 feeds till 50cm wide/high before running the maximum of three feeds.

IMPORTANT-Around 20% Runoff is a good amount; a good rule of thumb is to wait a  couple of minutes, as the coco acts like a sponge then lets out the  excess,

If the pots are smaller than 30Ltr then it may be necessary to water up to 5 times per day. Only water the plants in the day period. Do not over water plants as this will slow growth and can cause pest and disease  infestation.

Is it necessary to aerate the nutrient solutions?

YES. Aerating the nutrient solution is a good idea. It mixes constantly, protecting against stagnant water and improves plant health by adding oxygen to the solution.

What temperature should my nutrient solution be?  

Between 18 – 22°C. If solution is too cold use a water heater. If too hot, a nutrient chiller will be suitable. Cold nutrients slow growth, hot nutrients decreases oxygen from nutrients and increases chances of root diseases.

How often should I flush?  

Every 7-10 days is recommended. A small amount of nutrient in the flush solution (EC 0.6 ) will save the plant from any unnecessary stress. Make sure temperature and pH of flush water is correct.

Do not over flush as this can cause inconsistent PPM/EC/CF levels! A general guide is half the volume of water to the amount of media in the pot. For example; 50litre pot, 25litres of flush water. We also recommend using Dripclean in the nutrient solution to aid in the removal of built up nutrients in the medium.

What causes the tips of the plants to burn?

This can be caused by too much nutrient (too high EC), too much salt in the water, NOT enough water, lights too close or not regular flushing.  Certain nutrient deficiencies can also cause leaf tip burn.

Use a good nutrient of the highest grade and ask us to make a customised schedule to suit your needs!

As previously recommended, H&G Dripclean will protect the plant from built up nutrients in the medium.

What causes leaves to turn yellow?

This can be caused by a number of factors.

  1. Nutrient solution too warm (keep solution between 18 -22°C)
  2. Low oxygen levels due to lack of aeration.
  3. Over watering!
  4. The onset of root disease.
  5. The pH is too high.
  6. Too much salt in the water.
  7. Room temps too high or low.

All of these stop the plant from taking up nutrients in the correct quantities and balance.

Why do plants stretch?  

Plants stretch when the light is insufficient or humidity too high. Lack of ventilation is normally the cause of high humidity, also too many plants in a small area. A larger fan may help to fix this.

Why are my plant’s roots brown?

Brown roots are usually those that have been attacked by disease, probably Pythium.  Using “fongarid” will be of great assistance and usually eliminates the problem. Another frequent cause is over watering.

Normally, roots should clearly be white.  (Products that can ensure this are H&G Algen and H&G Multizyme).

My plants have very small bugs that spin webs. What are they?  

These are a troublesome pest known as Red Spider or “Spider Mite”.

They can cause severe damage and should be treated by spraying plants when small to prevent an infestation happening. Mite Rid or Spray safe will be suitable. If it is late in the flower stage then Mite Aerosol will be more suitable as this is a dry spray.

There are small black flies around the edges of my pots in the coco around root system of my plants.

Are they a problem?

Yes Scaria Fly Can Kill A Plant Easily If Untreated

The flies are probably Sciaria Flies also known Scarid and Fungus Gnats. Their larvae chew on and devour the fine root hairs of your plants; it is this damage that increases the risk of waterborne diseases like ‘Pythium”.

Canadian Express Nilnat or Angel Dust are very effective for the treatment of Scarid Fly. Fongarid will be required to treat for the disease left from the Fungus Gnats

What is the brown rotting in the flower buds?  

This is nearly always a disease called BOTRYTIS (grey mould).

To help prevent this you can use products like “Silikamagic” or “Bloom silica“. If you have this then Canadian Express PMT will stop the rot spreading through the flowers.

What are the white powdery spots on the leaves?  

This is probably a disease called powdery mildew. Powdery mildew is a disease that spreads by air borne spores that enter the grow room from the ventilation or when the door is opened. To prevent this try a bit more ventilation and if you have a severe case of powdery mildew try Canadian Express PMT.

This is a guide only! For a more detailed prognosis please contact our plant specialists to get a better diagnosis.