The Top 10 Mistakes That Drag Your Yields Down
Everest shares some time-honored heuristics to help beginner growers increase the productivity of their indoor gardens.
1.) Reduce Your Concentration!
Hydroponic growers adjust the pH of their nutrient solution to around 5.8 to 6.2 – this provides the best accessibility to the widest range of nutritional elements. pH adjuster products are sold in grow stores in concentrated liquid (sometimes powder) form. However, some growers get lazy and add this stuff neat (undiluted) to their nutrient solution. This causes nutritional elements to precipitate out of the solution and therefore become unavailable to your plants. To avoid this, make up a dilute solution of your pH adjusters – 1 part pH adjuster to 100 parts water – and use this instead. The weakened concentration of your pH up or down will enable you to safely adjust the pH of your nutrient solution without damaging your nutrients!
2.) So Near, So Far …
More light = more yield … but only to a point! In fact, grow lights can represent a mixed blessing for the indoor gardener. Sure, they provide the all-important light photons essential for photosynthesis – your plants ain’t growing without them! But these same lamps also generate a lot of radiant heat! If your plants grow too close to your lamps they will become too hot and shut down (stop photosynthesizing). In extreme cases they will scorch and burn and the growth tips will die. This causes untold stress to your plants and drastically reduces your yields.
On the other hand some growers are overly cautious and raise their grow lights too high, causing their plants to stretch in search of more lumens. The ongoing aim of every indoor gardener is to get as many growth tips in the “sweet spot” as possible. This is the area where your plants are just at a safe distance away from your bulbs and receiving maximum light intensity.
Different growers combat this problem in different ways. All growers should try to move the air in between the tops of their plants and the lamp using an oscillating fan. Some growers also air-cool or water-cool their grow lights while some put their lights on a mover or spinner.
As well as a light meter, use a thermometer with a remote temperature probe to measure the heat at the tops of your plants. For many popular indoor crops, the magic number is 82°F (28°C). What’s the temperature reading at the top of your plants?
3.) Brrrrr! Using Cold Tap Water!
First off, tap water can contain chlorine and chloramines plus high levels of other minerals (often not in a form that is useful to your plants) and other impurities. You should always feed your plants with the best quality water you can. Many professional growers and keen hobbyists take control over their water quality by investing in a water softener and reverse-osmosis water purifier. Also, you should always make sure that the temperature of your nutrient solution is around 65 – 68°F (18 – 20°C) before feeding it to your plants. Cold water shocks your plants’ roots and warm water contains drastically lower levels of dissolved oxygen. If your indoor garden is suffering from high temperatures, using a slightly cooler nutrient solution can help your plants get through until you manage to correct your environment.
4.) Lights++ Environment–
So, you’ve managed to dial in your indoor growing environment with two, three or four lights and you’re growing healthy, happy plants and enjoying regular crops of your favorite veggies all year round. Great, but don’t make the mistake of thinking you can expand by simply adding more lights! You need to also consider how this will effect your growing environment. Firstly, more plants will mean more transpiration, and a need for more CO2. More lights equals more heat to get rid of. So if you are thinking of adding more grow lights, make sure you budget for increased air transfer too – you’ll definitely need it!
5.) Unruly Plants
A crucial skill that every indoor gardener needs to learn is how to shape and train their plants so that they make the most of any artificial light source. You need to let your plants know who’s boss. Do not grow your plants too large. Small to medium sized specimens are the way forward for most indoor growers. Remember, your plants receive exponentially less light the further they are from the lamp. As most gardeners light their plants from above, a common goal for many indoor growers is for shorter, squatter plants with wide canopies. Think of a candelabra. Pruning out the leading growth tip will encourage many types of plants to adopt this formation.
TIP: If you are growing plants that are sensitive to photoperiod bear in mind that they will not respond immediately when you change your light cycle to induce flowering. Growers of many plant varieties are often stunned by the amount their plants bolt (or stretch) after changing the day length simulated by their grow lights. Err on the side of ‘small’ when deciding when to switch your plants from vegetative to flowering mode!
6.) Grow Like A Gardener, Not a Robot
So you think you’ve got your nutrient recipe down and now it’s just a question of making it happen. But the best growers are always in a state of flux. They are observing their plants on a daily basis, getting in among them, looking for signs of under / over fertilizing and adjusting their nutrient regimen accordingly.
This is especially important if you are making any chance, whatsoever, to your growing environment. Improved air exchange or CO2 levels in your indoor garden will cause your plants to grow more vigorously. The saavy grower observes and recognizes this and increases the strength of his nutrient solution accordingly.
Conversely, if the ambient temperature inside your indoor garden rises above optimum levels (e.g. during the summer months) your plants will inevitably use more water. You should therefore decrease the strength of your nutrient solution.
7.) Stale Food
Re-circulating your nutrient solution? Great – you’ll save on precious water resources, not to mention expensive nutrients and additives! But ask yourself – how often do you really drain your reservoir, then rinse, and replenish with a fresh batch? Once every week? Once every two weeks? Or once every … when you can be bothered? Younger plants will tolerate less frequent nutrient solution changes than more mature plants. But if you’re really going to turn on the charm, the time for super frequent nutrient solution changes is during flowering and fruiting. This is when your plants’ nutrient requirements are at their highest and will benefit most from regular nutrient solution changes.
8.) Poor Propagation
Care early on pays massive dividends later. Be especially patient and watchful during the propagation stage. Give your plants time to establish healthy root systems before rushing them into a hydroponics system and flowering them off. Ensure humidity levels are kept fairly high at 60-80%, especially early on. This reduces stress on the young plant which, in turn, allows it to focus on that all-important root system.
A plant that has been “hardened off” for five or six days under a fluorescent veg lamp, for instance, still needs to be introduced to a 1000W metal halide with care. Raise the metal halide 3-4 foot above the plants until you see the first signs of growth. Break those babies in slowly. What is often diagnosed as “transplant shock” is often more due to the shock of an increase in light intensity.
9.) Lack of Oxygen
Dissolved oxygen in your nutrient solution is so important we can’t harp on about it enough. Oxygen in your nutrients promotes root health and speeds up your plants’ metabolism meaning it can grow faster and bloom copiously! Lack of oxygen in your nutrients, on the other hand, invites all sorts of problems, the leader of the pack being pythium which can destroy your crop in a matter of days. You can increase levels of dissolved oxygen in your nutrient solution by bubbling air into it – the smaller the bubbles, the better!
10.) Don’t Be a Dirty Sanchez
What’s that carpet still doing in your indoor garden? Is that decomposing plant matter in the corner over there? Still not got rid of that bag of old root balls from last crop? Get a grip on your garden! Clean as you go. Keep it as spotless as possible. Filter all air vents. Think of your indoor garden as a laboratory and you won’t go far wrong. The cleaner your growing environment, the fewer viruses your plants have to fight; the more energy your plants can put into their primary mission – growing and blooming! Cleaning sounds boring, and it is. But how boring is 10% more yield? Nuff said.
Once my seeds germinate, they stop doing what they should be doing, namely branching out with secondary growth leaves. They just stay with one stem and the trunk goes up and up and wobbles over. I know it could be over-watering or too much coddling under saran wrap. I’ve tried putting under sunlight and keeping away from drafts, giving a temporary breathing by pulling away the cover. Cat grass was the only complete success, and I suspect even a cat could plant it!
Anna, Check to make sure your light source is only a couple inches away from the seedling. If the light source is too high this will cause the seedling to stretch and eventually topple. One of my favorite light sources for seedlings is a T5 Florescent.
I’m looking to do a non-circulating system sometime soon, but am worried that it may be hard to keep my nutrients at the correct level as I am topping off the water. What signs should I look for to see if there is too much or too little nutrients?
Also never interrupt the 12 hour dark period. The leaf colour is a good indication of overall plant health. (My experience.) You should buy a ppm meter or e.c. to be exact and remember you can add nutrients but it’s hard to ‘water-down’ if the stock tank levels rise.
How to overcome problems no 3,9. Depending where you live I used with success a 3 litre cola bottle. Do 5 bottles at the same time. Trick is to shake the water hard and smell (seriously) then add liquid nutrients. Be careful and measure exactly according to the feed chart. Personally I use a nurse’s syringe to be as accurate as possible. Then I use my ppm stick (parts per million), fill and measure a cup of nutrient rich water full a l.e.d number to ensure the strength. Basically ensure the number is what you expect. THEN leave 24+ hour with an air pump and small stone in the bottle. After 24 hours you can store for later or use as normal. This simple method 100% ‘helped my plants.’ I’d say it increased yield by 20% in soil. No expense just patience I guess also. With BIG thirsty plants in 15 litre pots and work I’d little if any spare time so I put (as an experiment) the pre-made water in bottles, then into the freezer. I know sounds mad in hindsight yet it worked a treat and saved me hours. The bottles when put into the freezer expand. Then I’d take the bottles out of the freezer 3L lump ice before work. I’d 5mins spare so I would leave the bottles in such a way that as the water froze they spilt but nothing leaked. The plant would feed during the lights on and by the time I’d finished work they’d almost be dry again – the bottles slowly dripped nutrient rich water into the soil. I’d 5 big plants, each had 3+ per day: without my effort I am sure they would have died. At the time after a day or 2 (about 4 years ago) I really thought I was producing co2 (I read about DRY ICE): to me, ice was ice! Those particular 5 plants produced a huge crop. Best ever, considering I had 9mins everyday, and re-stocked the freezer at weekends.
This is a simple solution to help with #1 and #3 which I learned from the fish aquarium hobby trying to emulate the very low pH and very soft waters of the Rio Negro tributary to the Amazon.
Use two 5 gallon buckets. The top one will be a simple filter and the second is the catch can. The filter is as simple as putting about 4 inches of filter floss (find in aquarium hobby) and fill the rest of the 5 gallon bucket with peat moss. Poke a little (1/8″) hole in the bottom of the top bucket and let it drain into the bottom bucket.
The result will be water with a pH around 5.5-6.0 and with a water hardness darn near 0. It will look a little like tea if it is done correctly. One bucket-full of peat moss can successfully filter 80-100 gallons of water before it needs to be replaced.