Medpot Minstrel: Hydroponics Medical Marijuana

Thursday, January 25, 2007


Starting a New Batch from Seed

You might have read an earlier posting in which I discussed the difficulties of my attempting to grow from clones. Being a very small medpot grower (I grow six female plants at a time under one 600W High Pressure Sodium light), the logistics of choosing a Mother Plant and isolating it on a different cycle from the rest of my ladies were baffling.

So I’m relying on my tried and true propagation method—growing from seed. I ordered ten Northern Flame seeds in a packet, since both Claire and I love the taste of this medicine. Since I normally start with 15 seeds, I also ordered 5 Afghani seeds, which were more expensive.

My freelance work has been scaled down by my clients, and as a result I’m working on a very tight budget. When you pay good money for your seeds, you want to make sure that they all germinate. So I was very careful in following the steps I usually take to germinate my seeds in rockwool cubes.

First, I soak the cubes in tap water overnight in a utility bucket. It’s important to do this overnight, to allow for the chlorine in the tap water to rise to the top of the bucket, so it doesn’t contaminate the germinating cubes.

In addition to the tap water, I normally mix in my basic fert at one-quarter its normal strength. So I mix in Sensi Grow A at one-quarter of what it reads on the bottle and Sensi Grow B, also at that reduced strength. I wait for the nutrients to dissolve. It is very important that these steps not be rushed.

Then I take a CF or a EC reading (Conductivity Factor-Electrical Conductivity). The recommended TDS (Total Dissolved Solids) level for pre-soaking rockwool cubes is 560 to 840 ppm, or CF 8-12, which is the same as CE 0.8 to 1.2. A CE 1 reading (same as CF 10) would mean that the solution is at 700 parts per million, which would be ideal for the pre-soak.

Then I take a pH reading. The ideal pH for pre-soaking rockwool is 5.5 pH, a tiny bit lower than the nutrient solution suggested pH for cannabis hydro grows (5.6 pH). The reason for the lower pH reading is that rockwool tends to be slightly alkaline, so this counteracts that bias.

If you get a reading lower than 5.5, very carefully add a small amount of pH Up, if the reading is higher than 5.5, conversely add a bit of pH Down. These agents tend to be aggressive, so they should be handled with care.

Never mix pH Up or pH Down at the same time—avoid this mistake at all costs. The chemical reaction would be totally unpredictable, and possibly violent.

Once all this measuring and pre-soaking is done, I take the rockwool cubes out of the solution and give each of them a light squeeze. This is done to reduce the moisture content by 10% to allow for air to penetrate the grow medium. The seeds that you put into the cubes need to breathe.

I use toothpicks all the time after meals—here’s another use for them. I use this very useful teeth cleaning tool to puncture a hole in the center of the rockwool, about 5mm deep. This is where I place my seeds very carefully, with tweezers.

I gently cover the hole with the material, but not too tightly. This creates a cocoon around the seed, with adequate moisture and nutrients and some air, a recipe for germination if there ever was one.

Depending on the variables, the seeds can take anywhere from twelve hours to twelve days to germinate, under a fluorescent grow light. The color spectrum of these tubes favors the blue end, which is as close to sunlight as you can get for this process.

The desired temperature for cannabis germination is around 23º C with the humidity level at 70-90%. I place my rockwool cubes into a tray with a transparent plastic lid to seal in the humidity.

Once the seeds are germinated, I have to be careful not to allow the humidity to reach 100%, so once in a while I take the lid off to allow for air circulation between the lights and the cubes.

Except this time my Northern Flame seeds germinated within a day or two, but the Afghani seeds wouldn’t budge. I waited and waited and waited. I must confess I didn’t have the patience to wait a full 12 days, so after a week or so I took the cubes with the Afghani seeds out, and removed the seeds very carefully, again with tweezers.

Plan B was to resort to that all-time favorite—putting the seeds between wet paper towels. I put these sandwiched paper towels between two large square plastic plates and made sure the edges were joined together to seal in the humidity.

I checked each day, making sure that the towels never dried out. After four days my Afghani seeds split open and sprouted tap roots, much to my relief. I placed these newly sprouted seeds back into the rockwool cubes where they came from and proceeded to wait for the formation of the first true leaves.

As more and more roots develop through the one-inch rockwool cubes, I usually transplant all my tiny seedlings into three-inch rockwool cubes, making sure that I’m very careful and gentle with these fledgling cannabis “kids.”
Eventually, when they look strong enough, I transplant a second time into six inch pots with a mixture of peat and perlite. I leave the rockwool attached to the roots, since it will disintegrate with time. These six-inch pots are then moved from the fluorescent environment to be under my 600W HPS light and an 18-hour a day, growth phase lighting regimen.

To reduce shock, it is advisable to move the seedlings slowly from one environment to another and to “harden” them by taking the lid off for longer and longer periods to enable them to get used to less and less humidity, then to place the six-inch pots around the periphery of the 600W light to begin with.

Advanced Nutrients makes two products that can be used at this time, No Shock and Jump Start, which are both designed to reduce seedling stress and to boost root and seedling growth at this crucial stage of the plant’s life.

A spray with Scorpion Juice when they’re a bit older will establish induced systemic resistance to many pathogens and pests.

With time, the six-inch pots can be moved toward the center of the powerful light and the selection process can begin. But that will be the topic of my next posting.

posted by Wes @ 10:45 PM 0 comments links to this post

Thursday, January 18, 2007


Harvesting Your Buds, Processing Them Properly

Last week was week 6 of the bloom cycle for my six ladies, time for the final round of nutrients and supplements.

My 72 Liter reservoir at moderately heavy feeding took 163.44 mL of Sensi Bloom A, the same amount of Sensi Bloom B, as well as 28.8 mL each of Mother Earth Super Tea Bloom, Grandma Enggy’s Humic Acid, and Grandma Enggy’s Fulvic Acid.

As a final vitamin shot I added 302.4 mL of B-52, and to prevent any last minute pathogens or pests, 10.08 mL of Barricade. I made sure to add this last ingredient the night before, to allow it to completely dissolve in my pre-mix tank.

30.24 grams of Carbo Load Powder came next. I used to use Carbo Load Liquid back in the days when I nourished my medpot plants with an organic regimen, but the powder is just as effective and less costly.

504 mL of SensiZym ensured that my baked clay pebbles would be cleaned by the living enzymes in this product, which munch on root debris in your grow medium.

This is beneficial since the debris get converted into a form that is easily absorbed by the roots, as well as because this process cleans your grow medium so thoroughly, that you’re ready for your next planting.

Piranha, Tarantula, and Voodoo Juice were last added during week 2 of the bloom cycle, they are no longer required at this time. These root colonizers have done their work, aiding nutrient absorption and promoting root and plant growth.

Bud Blood and Big Bud Powder were added during weeks 1 and weeks 2, 3, and 4 respectively. Don’t make the mistake of adding either of them at this time. Overdrive is the only bloom enhancer that gets added during weeks 5 and 6 of bloom. This week I added 201.6 mL of this much heralded product.

I also added Sweet Leaf to my mix, in order to ensure a sweet tasting harvest. Some growers question the wisdom of adding both Carbo Load and Sweet Leaf, since they consider it redundant.

I, however, have nothing but praise for Sweet Leaf, which guarantees me and Claire the best tasting medicine possible. Carbo Load adds carbohydrates for growth, Sweet Leaf adds them for taste.

This is week 7 of bloom, so I’m flushing the entire six-bucket ebb and flow hydroponic system. The only thing I’m adding is 180 mL of Final Phase, which gets rid of any chemical taste or residue that might be left from either my basic fert or the additives.

I’m already checking my resin trichomes under a cheap microscope to see if they have become transparent. Once they turn brown, you’ve missed the optimum time for harvesting your medpot.

Some growers suggest harvesting from the top. I find this to be a useful suggestion, since the buds closest to my 600W High Pressure Sodium light fixture are the ones that mature the fastest.

Always use a sharp pair of scissors to cut your buds. It helps to disinfect them with isopropyl (rubbing) alcohol. You can also use Advanced Nutrients Wipe Out to clean your tools and working trays.

You must prepare a drying space for your buds, which must lose all their water content before they are ready to be cured.

My grow room is next to my home office in the basement of our house. I have a large closet opening from my office that is perfect for drying cannabis. I put a thermometer and a humidity meter in there, as well as a fan to help circulate the air.

I string a wire across the top to hang my bigger buds and for the smaller ones I use a window screen on a small table, propped up my four bricks, one in each corner. The bricks are to allow circulating air to get under the screen.

It’s best to dry your buds in total darkness, since daylight robs them of some of their potency.

Prior to drying, your buds should be manicured—that is, all the excess fan leaves should be removed with the sharp scissors. Some growers trim their buds lovingly, as if giving them a haircut.

I weigh my buds wet and then again when they’re dry, usually in seven to ten days. Buds lose up to 75 percent of their weight in the drying process. Once I had a bud that was too heavy and big to hang with a clothes pin, so I bought a lingerie bag (any netted bag will do) and hung it in that.

You should consider yourself fortunate if your buds are so big that a clothes pin will not hold them up on your drying wire.

Turn your buds frequently to face the fan and make sure that the humidity in the enclosed space is kept low. I open the door of the closet frequently, to let the wet air escape and dry air to enter.

In cold, wet weather I use a small, portable electric heater to keep the temperature in the room high enough to allow for drying.

You may test your buds for dryness by trying to bend them. If the stalk snaps, the drying process was successful. If it still bends, dry the bud some more.

Once the buds are completely dry, they are ready for curing. I prefer to use glass jars for this process, but you can always use metal coffee tins or Tupperware in a pinch.

Place the well-dried flowers in the container and store it in a cool, dark place. Open the lid every day and turn the buds, to make sure that the CO2 and other gases have a chance to escape.

Repeat this daily ritual for about two weeks and sample your medicine. When the smoke and taste are to your liking, your cannabis is cured.

If you keep your container away from light and heat, your medpot should have a long shelf-life. I keep my containers in our freezer with the lid tightly shut. If the lid is not on properly, moisture could get into your pot, causing problems such as mold and mildew and loss of potency.

Harvest is an exciting time for me and I look forward to it any day now.

posted by Wes @ 7:40 PM 0 comments links to this post

Thursday, January 11, 2007


Electrical Conductivity (EC) converts in funny ways

I was concentrating on parts-per-million (PPM) in my last posting. Since then, I’ve spoken to the Advanced Nutrients Medical technical help line and found out that they’ve decided to go with Electrical Conductivity (EC) values, rather than PPM.

Don’t panic. Their Nutrient Calculator still shows both numbers, so if you’ve got a PPM meter and don’t have any way of measuring EC at the moment, you can still continue using that very valuable tool to figure out the weekly diet of your cannabis plants.

Since many of us medpot growers find these different values confusing, how is this for a scoop? Even their tech guy admitted that it’s confusing! No use fretting about it—you’re not the only one who can’t figure out EC and CF and TDS and PPM, and how they all fit together.

Then the AN guy went on to relate how three different meters read EC 1. Electrical Conductivity is measured in microsiemens per centimetre.

EC 1 on a Hanna pen meter will read as 500 parts-per-million.

EC 1 on a Bluelab Truncheon meter will read as 700 parts-per-million.

EC 1 on a Utech EC meter will read as 640 parts-per-million.

Advanced Nutrients Medical has decided to go with the Bluelab Truncheon CF/EC/PPM Meter, which is manufactured in New Zealand and measures each microsiemens (mS) per centimetre as 700 PPM.

PPM and Total Dissolved Solids (TDS) are the same thing. Total dissolved solids in your nutrient solution are measured by gauging the charge between two probes—not resistance, but the conductivity of the dissolved particles.

Depending on the strain of cannabis you’re growing, the ideal EC reading might be 0.7 to 1.5 mS during the vegetative stage and 1.0 to 2.0 mS during the flowering stage. The Nutrient Calculator bears this out.

The hydroponics industry considers EC readings to be more accurate than PPM readings. CF is exactly 10 times your EC reading. So if you have a CF meter and measure 10, that reading is equivalent to EC 1.

When I was growing my medpot using Iguana Juice Grow and Bloom, plus assorted organic supplements, I was tempted to boost the size of my buds with a touch of synthetics, by adding Bud Blood, Big Bud, and Overdrive to my reservoir.

When it comes to ogranics, the Advanced Nutrients plant scientists have yet to figure out the exact amounts to use of these 3 very potent synthetic bloom boosters in terms of EC, PPM, CF, or TDS, whichever abbreviation you’re most comfortable with.

The PPM numbers in the Nutrient Calculator are merely guidelines, according to the AN tech guys. In other words, some plants like very light feedings, other plants like heavy feedings. It’s just like humans—one diet definitely does not fit all.

This is where the metering comes in. Start with a medium-feeding regimen. If you’re plants develop yellow tips, then you should decrease your concentration. If you don’t get yellow tips, it may imply that your plants are able to take a little bit more food.

Growing medical cannabis is basically experimentation. If two of your plants bolt toward your HID light, while the others are slower to grow, you should pinch the top shoots of your bolters or trim their tops entirely, to give the slow growers a chance to catch up.

If you raised your light to accommodate the fast growers, the slow growers wouldn’t have a hope. But if you pinch the top shoots of the fast ones, they’ll bush out and give the rest a fair chance.

The same way with diet. If you see any signs of calcium deficiency, include Sensi Cal Mg Mix Grow or Bloom in your nutrient regimen. If your plants show any sign of stress, feed them with Organic B or B-52.

Always be conscious when you’re adding new ingredients to the mix that your total NPK does not exceed desired levels. Keep taking pH readings and make sure that your acid-alkaline balance is at the optimum level for hydro, which is 5.6.

The temperature of your nutrient solution is also a variable and that is why some meters have an automatic temperature adjustment. The Bluelab Truncheon has automatic temperature compensation up to 78 degrees Fahrenheit.

The Truncheon is fairly reasonable in terms of price ($139.00). You’ll also need a Bluelab CF/EC cleaning kit for $24.95, since the probes have to be clean and uncontaminated for accurate readings.

For $289 you could buy a Bluelab Combo Meter, which measures pH, EC/CF/PPM, and Temperature as well. Bluelab offers calibration solutions in order to ensure that your meter is measuring your real acid-alkaline balance, and not some distortion.

Nutrients assume the form of ions when in solution. The ions in your reservoir represent the entire spectrum of minerals needed for plant growth.

My basic nutrient, for instance, is Sensi Grow A&B and Sensi Bloom A&B. In addition to the macro nutrients of Nitrogen, Phosphorus, and Potassium, this Advanced Nutrients 2-part is species-specific in including all the micro-nutrients necessary for growing robust cannabis plants.

The same goes for the classic 3-part, Grow, Micro, and Bloom, as well as Sensi One Grow and Sensi One Bloom. Each basic plant nutrient was carefully designed to meet every nutritional need of your valued cannabis plants.

So investing two or three hundred dollars in a sensitive meter to make sure that your plants are getting the proper diet in appropriate servings is not such a bad deal.

If your nutrient solution has more ions then it will read a higher EC value, since there are more ions to carry the charge from probe to probe.

EC translated into PPM using one of several conversion factors. Depending on which factor you use (the 442, the NaCl, etc.) EC 1 either means 700 PPM, 500 PPM, or 640 PPM.

It’s not unlike the confusion caused by American (or Imperial) weights and measures vs. Metric.

Be aware that Advanced Nutrients is using the 700 PPM standard, and the rest will fall into place. If you’re using a lot of their products (as I am) it would help if you bought a meter that uses the same standard.

posted by Wes @ 11:13 PM 0 comments links to this post

Wednesday, January 03, 2007


Bloom Boosters change PPM of Reservoir

I’m on weeks five and six of the bloom cycle, so I’m adding Overdrive to my ladies’ reservoir. Weeks two, three, and four I was adding Big Bud Powder, which is very economical to use, and contains 19 amino acids that act as building blocks for the flowering sites on my cannabis plants.

Bud Blood, which was given during week 1 of flowering, helps initiate the flowering process. Big Bud confirms the location of the flowers and delivers the amino acids that are converted into proteins and alkaloids in order to provide the energy boost needed for flowering. Then Overdrive clinches the process by helping with girth, weight, and taste development.

These three Advanced Nutrients Medical bloom boosters cannot be given at the same time—only in sequence. Were a grower foolish enough to mix them into his reservoir all at the same time his cannabis plants would be fried to a crisp, according to the tech guys at Advanced Nutrients Medical.

The plant scientists at that company have figured out the exact parts per million (ppm) that results when these bloom enhancers are added to the mix on top of all the other ingredients that their Nutrient Calculator suggests for the flowering cycle.

As you know, my basic fert is the classic, cannabis-specific 2-part, Sensi Grow A&B and Sensi Bloom A&B. The size of my reservoir is 72 Litres. I’m more comfortable using Metric, the international standard, rather than the Imperial measurements, which I find confusing.

During week 1 of flowering, while adding Bud Blood to the mix, my ppm was 1000. Weeks 2, 3, and 4 saw me adding 27.36, 33.12, and 38.88 grams of Big Bud Powder respectively, raising the total ppm of my mixture from 1268, to 1533, to a peak of 1800ppm during those three weeks.

Then comes now, weeks 5 and 6, time to add 230.4 mL and 201.6 mL of Overdrive, to reduce the ppm first to 1600, then to 1400. Literally nothing is added to the reservoir during week 7, only 180 mL of Final Phase, bringing the ppm down to 300.

During the flowering stage, in addition to my basic fert and the bloom boosters, Advanced Nutrients Medical recommends adding Mother Earth Super Tea Bloom, Humic Acid, Fulvic Acid, B-52, Barricade, Carbo Load Powder, Sensi Zym, Piranha, Tarantula, and Voodoo Juice. Consult the Nutrient Calculator for exact quantities.

In addition to Potassium, Phosphorus, and Magnesium, Overdrive also contains Ascorbic Acid, Fulvic Acid, and Folic Acid. I remember when Claire was pregnant with Squirrel—the doctor urged her to take Folic Acid regularly. That’s because it plays a major role in cell division and is an essential ingredient in healthy reproduction.

Don’t forget that flower formation is basically just one step in fruit and seed production—the cannabis plant’s reproductive cycle. We choose not to allow male pollen to fertilize the buds that our ladies produce, since in most cases we do not want them to go to seed.

We must also remember that by going to a lighting regimen of 12-hours of light, followed by 12 hours of total darkness, we are cutting back on the amount of light available for photosynthesis. The production of carbohydrates (sugars) is thus curtailed, even though these energy sources are needed more than ever during the flowering stage.

So we add Carbo Load Powder all throughout the flowering cycle, in order to replenish the energy required to form the desirable large buds we all crave. Ascorbic Acid and Folic Acid are essential to enable the plant to go into overdrive with the photosynthesis process and produce adequate energy to reproduce or attempt to reproduce.

In addition, Fulvic Acid is necessary to provide a “molecular tonic” at this time to aid in the transportation of sugars and other nutrients throughout the plant, provide chelation, and enable bio-reactivity in my six cannabis ladies.

Used in sequence, the three bloom enhancers result in large fragrant buds, abundant resin production, and a higher THC content, or Advanced Nutrients Medical will give you your money back.

posted by Wes @ 3:08 PM 0 comments links to this post