Here is solid run-down of what you need to do to become a “Perfect Grower.” Some of you may know a lot of this already, others may not. It’s worth taking the time to read through it, compare notes and take away some helpful information to achieve bigger and better harvests.

First and foremost, your growing environment is the single most important variable under your control. For indoor and greenhouse growers, all-in-one units that measure temperature, humidity and CO₂ levels are invaluable. At the very minimum, you need to know your temperature and humidity. Always keep these monitors as close to your canopy as possible.

Environmental Targets:

These environmental targets are at canopy level:

Vegetative Stage:

Temperature Target: 75F (Acceptable range 70-85F)
Humidity Target: 58% (Acceptable range 50-63%)

Flowering Stage:

Temperature Target: 75F (Acceptable range 70-85F)

(Some genetics can take upwards of 85F)

Humidity Target: 55% (Acceptable range: 45-58%)

Indoor and greenhouse growers should reduce humidity to 40-45% during the last 1-2 weeks of flowering.

You can reduce stretching and internode spacing during the first 2 weeks of bloom by keeping your day and night time temperatures the same (for example, 75F lights on, 75F lights off).

If you’re injecting CO₂ above 800 ppm, temperatures should be between 80-87F. Be careful using CO₂ levels above 1300 ppm.

If you are not injecting CO₂, you need to make sure you have enough fresh air exchange to keep the room or greenhouse close to atmospheric CO₂ levels. This is around 380-400 ppm of CO₂. Fast growing plants will use up available CO₂ in a room quickly. Low CO₂ levels are a silent killer, affecting both yields and flower quality.

CO₂ will settle. Circulate air around the growing environment, both above the canopy and below the plants. Avoid blowing strong wind directly on your plants.

Reverse osmosis units are highly recommended and money well spent. If you use tap or well water, plug the values into your feeding chart so the system can make the proper adjustments.

Nutrient Targets and Nutrient Dosing:

It’s important to understand that overall EC/PPM readings are not universal across nutrient lines. This means if you feed an EC of 2.6 (1300 PPM) with one nutrient line, you should not try to match this EC level with Perfect Grower.

Why is that?

We need to break down EC/PPM into two different things...

EC derived from Mineral Nutrients

Mineral nutrients are the core of a plant’s nutrition and a contributing factor to the overall EC of your nutrient solution. These are your elements in solution – Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Sulfur, Iron etc.

Each mineral nutrient has an electrical charge and some are stronger than others. Increasing or decreasing any of these minerals will change your overall EC.

EC derived from organic inputs

Organic inputs can also increase the EC of your nutrient solution. These include humic/fulvic acids, amino acids, carbohydrates and kelps. These inputs will increase the EC of your nutrient solution without necessarily supplying any mineral nutrients to your plants.

Our feeding charts give you a very good baseline of where your nutrient levels need to be based on how you grow. To get to perfection, you need to monitor and adjust these nutrient levels based on runoff, pH changes and overall plant growth. Different genetics and growing styles can demand different feeding requirements. It is important to note that small adjustments to your nutrient levels are always better than drastic ones.

In order to make the proper adjustments, you need a good pH probe and EC/PPM meter. Keep your equipment regularly calibrated using both a 7.0 and 4.0 buffer solution. The same is true with your EC/PPM meter.

Target Runoff pH Levels:

Soil: 6.5-6.9
Promix: 5.8-6.3
Coco: 5.6-6.1
Hydroponics: (no substrate) 5.5-6.0

Nutrient availability is greatly affected by the pH of a solution and substrate. Companies that say pH doesn’t matter are preaching bad information. Monitoring and adjusting your pH is one of the most important things a grower can do for bigger and better yields.

When you feed any potted plant, the “runoff solution” will be a combination of your new feeding plus the unused nutrients left behind from the previous feeding. All substrates (coco, soil, peat moss, etc.) will hold on to nutrient solutions and must have their runoff analyzed regularly.

How To Analyze Your Runoff and Adjust Your Nutrient Dosing

In hydroponics and recirculating systems, keep an eye on the EC and pH of your solution.
Adjust accordingly and keep the reservoir topped off with fresh water.

All potted plants should be elevated off the ground so runoff can be collected.
Never let your plants sit in their runoff solution.

As a grower, it is your job to make adjustments based on this information for the next feeding. It is not necessary to analyze runoff from every single plant. You do, however, need a good sample from a variety of plants. If you have 15 plants, collect runoff from 2-3 plants and combine the solution into a bowl or dish. Use your calibrated pH and EC meter to test your sample runoff.

High pH Reservoirs and Runoff:

High pH comes from two things - media buffers and nutrient absorption. Substrates like rockwool have a naturally high pH. New rockwool in a recirculating system will increase the pH of your nutrient solution until the media has equalized.

The second way your pH increases is the absorption of anions. Anions are negatively charged ions and the major ones in solution contain nitrogen and phosphorous. Increases in pH are commonly seen with large vegetative plants fed solutions with a large portion of nitrogen-containing anions.

High EC/PPM in Reservoirs and Runoff:

Above 2.4 mS/cm (EC) | 1200ppm in Vegetative
Above 3.5 mS/cm (EC) | 1750PPM in Flowering

Your plants are leaving behind nutrients and your substrate is absorbing them. When this happens, the next feeding should always be pH’d water. The pH of your water feeding will depend on the pH of your runoff (explained in the pH section below). When you have a high EC runoff, take a look at your nutrient profile strength and overall balance.

Are you feeding aggressively?

If so, reduce your overall EC.

Is your profile out of balance?

Pushing elements too high or too low will cause absorption problems. If the balance is not there, nutrients will be left behind and runoff concentration will increase.

Low pH in Reservoirs and Runoff:

Low pH comes from mainly three things - microbial growth, media and nutrient absorption. Microbial growth can come from both beneficial and harmful bacteria. If your plants look unhealthy, root diseases are very serious and must be addressed as soon as possible.

Organic media where organic decomposition reactions take place – like peat moss – can also tend to create an acidic pH. If this is the case, apply top dressings like oyster shell flour to reduce this effect through the growing period.

The last reason for low pH is the absorption of cations. Cations are simply positively charged ions. Calcium and Potassium are the major cations in solution. Decreases in pH are commonly seen during the flowering stage.

Balance is everything.

Plants need enough Nitrogen to properly absorb Potassium and stabilize the root zone pH. The lower you push Nitrogen, the lower your pH will drop. If your pH becomes too low for too long (below 5.5 in soilless), Potassium absorption will slow and micro-nutrients can become toxic as their absorption becomes much more efficient at low pH values.

Low EC/PPM in Reservoirs and Runoff:

(equal to or below what you are actually feeding):

You have the option to increase the strength of your nutrient solution. Our feedings charts have a button on the top that will equally adjust the overall concentrations for you.

How To Correct and Manage Your Substrates

Substrates must be corrected through nutrient dosing and pH management. If you have a runoff issue, you should not try to fix it overnight. This will stress your plants and cause more harm than good. It takes time to properly equalize an unbalanced medium. The more incorrect feedings you do, the worse the situation will get and the more time it will take to correct. This is why consistent monitoring of your pH is important.

Examples:

What you should not do:

My runoff pH is 5.0 and my EC is 3.0! I am going to run 3x the amount of fresh water pH’d to 7.5 to fix this problem.

What you should do:

1. Any time you have a high EC reading in runoff, your next feeding should be pH’d water. If your pH is low, give the plants a good healthy feeding of fresh water pH’d to 6.5. If the pH is high, use a pH of 5.5. This will not fix the problem immediately, but it will help your plants safely adjust.

2. The next step is to understand why the pH is low or high. The first thing to check is your Nitrogen-to-Potassium ratio. These 2 elements are the workhorses in plant nutrition. If Nitrogen is low and Potassium is high, your pH will continually drop. Slowly bring your Nitrogen and Potassium levels closer together until your pH equalizes. If you are feeding aggressively on the feeding chart, reduce your concentrations to normal on your next nutrient feeding. If you are feeding normal, keep it there and proceed to step 3.

3. Make corrections with the pH of your water or solution in a moderately high (6.2-6.5) or low (5.5-5.8) range depending on how the runoff needs to be adjusted. Do not feed above 6.5 or below 5.5 in soilless substrates (coco, promix etc). In soil, pH corrections from 6.3-7.1 are acceptable.

If your runoff EC is higher than what you are feeding, that is ok and your plants are doing just fine. Again, if runoff exceeds 3.5 EC (1750 PPM), proceed to a “water only” feeding and check your ratios again. Make minor pH adjustments to your nutrient solution to go up and down within the acceptable ranges of your medium.

More Important Information:

1. Always keep reservoirs heavily aerated and covered with water temperatures between 65-75F.

2. Hydrogen Peroxide will oxidize and destroy expensive biostimulants in our products. If you must use hydrogen peroxide, use it during “water only” feedings.

3. Check your leaves and substrates regularly for nutrient and pest issues. If you have a nutrient problem, check to see where your levels are for each product. If you are having trouble, contact us and we will help you figure out the problem and find a solution.

4. The best harvests always come when the time and effort is put in. This involves consistent pruning, early trellising and monitoring your environmental and nutritional details.

5. Use safe pesticides/fungicides/miticides even when bugs and diseases are not present. Preventative maintenance is worth its weight in gold – keeping bugs and diseases away is much easier than killing a thriving infestation.

6. In hydroponic systems with no substrate (pure hydroponics), water only feedings are not recommended, even during the later flushing periods. Mild, low EC feedings will bring much less stress to your plants. Water only can be used for a short period of time to purge the system of salt buildup.

7. Your plants can catch the Tobacco Mosaic Virus. Smoke tobacco away from your crop and wash your hands well before touching any leaves.

8. Calcium accumulates in substrates (soil, Promix, coco etc.) as well as in plant tissue. Calcium will compete with Potassium for absorption. Tap and well water can contain a good amount of Calcium. If you are using tap water with high-to-moderate Calcium levels, you should use little-to-no Ca-Mg product. Our feeding charts will automatically adjust these numbers for you if you plug in your tap water information.