Posted on by Alex Russell

Hydroponics: Rookie mistakes you want to avoid

You would be surprised how many times we see people make these simple rookie mistakes, hopefully a quick read through this article can save at least one person from making these costly errors!



After setting up a new grow room, hang your light(s) inside your room and power them on, close up the grow room and turn the light off in the outer room and observe if any light is coming out from your now closed grow room, spilling out to the outer room. If you now notice light beaming out from any point of your internal grow room, you have a light leak that will cause major issues to photoperiod plants and your room is not a suitable space to grow in until this issue is fixed.

Commonly, light leaks are found around ventilation ducting holes, zippers, hinges or cable holes. Be sure to check every corner of your grow room and patch up any found leaks, followed by a re-test until no light is able to leave your grow room.



One really common mistake growers can make is connecting their new ventilation system with the fan airflow direction the wrong way around, always ensure the flow of air is going the way you need, on the Can-Fan and most reputable brands there should be an arrow indicating which direction airflow is going.

Once you have lined up everything, connect together using a combination of sturdy tape and steel ducting clamps to secure tightly, then hang ventilation system inside your grow room or place outside your grow room, making sure the direction of your fan is relative to the filter location.

If you have your filter placed inside your room, you want your fan's airflow directing away from the filter, to pull/push air out of your room, thus pulling air into and through the filter from inside the room, exhausting outside.

If you place your filter outside your room, you want your fan's airflow directing into the filter, pulling air from inside your grow room and pushing it out through the filter which is outside the room, exhausting and scrubbing air outside the grow room.


Another issue that is more common than you think is some growers actually do not know how to mix A/B nutrients correctly.

Remember, they are in separate bottles for a reason. ALWAYS add water to your jug or tank first, then add A, then mix, Then add B and mix, then adjust and so on.. NEVER add the raw ingredients on their own before water, they will react with each other and form insoluble compounds that neither can be broken down by water or consumed by the plant.

Another common mistake is double dipping. Always make sure you never mix concentrated nutrients together without dilution, this includes when using a syringe or pipette in one nutrient bottle and then dipping into another without properly clearing your measuring tools first.



Many growers, new and old, have a misconception that more light equals more yield. While this can be true up to a certain point, once that point is reached, more light will actually work the opposite, reducing overall yield and potentially causing so much stress you get no yield. This is a common misconception that came out of years of growing with underpowered lighting systems, that when additional light was added, increase of yields were the result. This was a misunderstanding of the powered of their main light.

Now that horticultural LED systems have exploded into the market, it has become easy to acquire a lighting system that produces significantly more light than a plant can handle. Quantum meters are used to measure the quantity of light coming out of a light source, similar to how a EC/PPM pen works for measuring nutrient strength, however, Quantum meters can be costly and out of the reach of most growers.

The best advice we can give to LED users is to factor in the amount of energy the system consumes and gauge their lights distance to canopy from that. For example, we recommend these distances as guidelines to use with a LED light:

Power - Distance:

  • 100W - 15-20cm
  • 200W - 25-30cm
  • 300W - 35-40cm
  • 400W - 45-50cm
  • 500W - 55-60cm
  • 600W+ - 65cm+

Keep in mind these numbers are guidelines, as the spread of diodes and light coming from the fixture will alter these numbers slightly.

In the case of using a HID light (HPS, MH, CMH), you will usually see the heat radiation from the lamp burning the canopy before you reach excessively light levels from a HID system. This can help guide growers to what a safe distance from canopy for their light is.


If these suggestions and tips help stop just one rookie from making these mistakes, our job of writing this article is done!