Here are some definitions and abbreviations.
Nitrogen (N)
Phosphorous (P)
Sulfur (S)
Potassium (K)
Calcium (Ca)
Magnesium (Mg)
Hydrogen (H)
Oxygen (O)
Carbon (C)
Iron (Fe)
Chlorine (Cl)
Manganese (Mn)
Boron (B)
Zinc (Zn)
Copper (Cu)
Molybdenum (Mo)
Carbon Dioxide (CO2)
Hydrogen Peroxide (H2O2)
DO: Dissolved Oxygen, A measure of the amount of oxygen in suspension in a nutrient solution.
RO: Reverse Osmosis, Water that has been forced through a very solid membrane to remove suspended particles.
H2o2: 35% Hydrogen peroxide.
Max dose = 2.5ml/gl
HID: High Intensity Discharge, HID lights fixtures include MH and HPS
HPS: High Pressure Sodium light
MH: Metal Halide light
Conversion bulb: A bulb designed to convert a mh to hps or visa/versa
tub/bucket/tank: rez
rez: Reservoir
Rez level: the top of the nutrient solution in your rez, always maintained at a specific volume marked in your rez, or with a sight tube. It is very important to make sure your rez is it at the full level mark before you measure ph or ppm.
nutes: Chemicals designed for hydroponic growth.
nute load: The max amount of nutrients reccommended by a nute mfg,
expressed as a percentage. He is using a 50% nute load.
solution: a mixture of hydroponic nutes.
ph: a measure of the hydrogen ions available in your nute solution.
Buffer: A chemical suspended in your water that acts like a sponge to absorb acids, in tapwter it will be Calcium-carbonate. If you use RO, then you can use Potassium molecules for buffering, without the damage caused by excess Ca.
tds: Total Dissolved Solids, a measure of some the suspended chemicals in your nutrient solution.
ppm: Parts Per Million, a number representing the tds in your nute solution.
EC: Electro conductivity, a measure of the salts in your nutrient solution. tds, ppm and ec are all the same measurement, just expressed in different values.
AN: Advanced Nutrients, a company that mfg nutes.
DM: Dutch Master, another nute mfg
GH: General Hydroponics, another mfg.
CM+: cal mag plus is an additive made by Botanicare.
LL: Liquid Light, a foliar spray made by DM
MET: Mother Earth Tea,
Organic hydro nutes, grow and bloom, by AN
Conni: Connoisseur, a bloom nute by AN
Grow medium: A method to establish the sprout,
the method used to hold the plant in the water.
Ususally Coco Coir plugs and Hydroton Clay pellets,
Neopreme plugs, or Rockwool.
ml: metric measurement Milliliter.
L: Metric measurement of Liters
g/gl: US measurement, Gallons
g/gr: Metric measurement, grams
VPD: vapor pressure deficit
Power head: A pump used in aquariums to increase DO
Air pump: Another tool used for increasing DO
1. You must purchase an accurate ph meter
before you plant your first seed.
2. If you choose to grow without a ppm meter,
you must carefully follow the nute mfg directions,
to avoid nutrient burn, and you should use a reduced nute load.
3. Your rez should have a drain system with a pump,
to make nute changes fast and easy.
This will save a lot of time and spills, and pay off greatly.
4. If you grow with tap water,
you should reduce the nute load by 50%.
5. Use RO water, unless you have very low ppm tap water.
6. Use these two rules to determine when to change your rez.
a. The Add back rule.
b. The pH rule.
7. Low ppm nute solutions are easy to correct, but even slightly high nute solutions can cause irrepairable damage. Nute Mfg test their chemicals using commercial RO machines(000ppm), and very controlled temperature and humidity. Always use less nutes(chemicals) unless you are able to copy the nute mfg environment exactly.
8. 3.5-5gl/plant, is a good rule of thumb for estimating efficient rez volumes.
9. Start your seed in the medium you are going to grow in. All seed companies recommend this practice. Use the best genetics you can find.
10. Seeds can live on the stored energy they are sprouted with for 10 days. Don't feed new sprouts for at least 7 days, and then you should only use 1/4 strength nute solutions for the first week.
11. Always completely change out the solution with fresh water,
and then add new nutes.
12. Never adjust the pH of the water before you add it to the solution. Pre adjusted pH'ed water will not be stable. Add clean water to top off your rez, and then measure the pH, then adjust the pH.
13. Don't burn the flavor out of your plants with HID lights. Sure more light equals faster growing, but why would you want to quickly grow hay? Use lights close during veg and move them further away in flower. Strong evidence supports the use of UVb lights to increase potency.
14. Buy a 60 to 100 power pocket microscope. You can see bugs, their eggs and, near harvest time, you can check trichomes.
15. Use Bed lice spray from the drug store to aggressively attack spider mites. Permethrins will cause the eggs to destruct. Spray under the leaves to kill the eggs. There will be no residue from this product because it breaks down with uv light.
16. If you use RO water, AN Barricade is an excellent limited buffer with a very small dose. Do not exceed Barricade's recommended application rate. Use an eye dropper to deliver Barricade, and check the pH between each drop. Barricade will raise the pH.
17. Use metric calibrated eye droppers, syringes, and baby medicine spoons, for very accurate dosing of nutes, and for ph adjustment.
18. Too low humidity can cause VPD.
19. Insulate, shade, or isolate your rez from light, and heat. Air blowing over the surface of your rez, will reduce the temp by 7-10º.
20. A fan to move air over the plant is required.
21. Have a power head in the bottom of your rez to keep the solution moving all the time, along with your air pump.
22. Uncontrollable pH swings can indicate a diseased root system.
If your pH is falling to 3 or 4, this would be a good indicator of advanced root rot.
23. The max dose for 35% H2o2 is 2.5ml/gl.
24. Control is what gives hydro the growing edge. Control results in better flavor, faster production, and higher yields. You can control the water, the air, the temperatures(rez & air), the humidity, the nutes, the ph, and the light.
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Here is the Add Back & pH rule.
It is important to follow these two rules until you have completed a full grow,
and they are especially important if you are not using a tds meter.
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1. The Add Back Rule : Once you have replenished the original rez volume with fresh water, then it is time to change out the rez with fresh water and new nutes.
Never add nutes between nute changes,
until you have experience with the nutrients you are using,
and then you must have a tds meter.
Add fresh water once or twice a day to maintain the rez volume.
Do not adjust the pH before adding water to the rez.
Most of the time you will find that adding fresh water to top off the rez, will bring the pH back to normal range.
Check the pH and adjust if necessary, after adding water to top off the rez.
If you have a 5 gl rez, and you have added 5 gl over the last few days to maintain the rez level at the full mark, then it is time for a complete change out.
Keep and re-fill your plastic jugs to help maintain your add back count.
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2. The pH Rule :
There are separate pH rules for RO and tap water.
We will discuss RO first.
With RO, you will control the buffers.
There are three chemicals
that will allow you to get a stablized nute solution
without causing any nutrient lockout.
First you need to get some AN Barricade
which is Potassium Silicate.
You should also get some Potassium Carbonate,
and Potassium Hydroxide.
I buy these two chemicals premixed
in the powdered form from GH,
and then add RO to make a solution,
which I use to increase the pH with my eye dropper.
So here is the drill.
Add the nutes and any additives you are using,
and then measure the pH. (do not add Barricade until the pH falls below 5.6)
Most of the time the ph will be around 5.6
right after you add the nutes.
In a few hours check the pH
and it will be down as the buffer is overcome.
(I let it go down until 5.2-5.4
and then add Barricade to bring the pH up to 5.6).
Add one drop of barricade per gl,
and then check the pH.
( you need an eyedropper)
Keep using Barricade to bring the pH back to 5.6
until you have reached the max dose of .5ml/gl
(5 drops/gl of barricade max)
After you have maxed out the barricade,
then the next time the pH falls,
start using the GH Potassium Carbonate/Hydroxide powder in RO solution,
to bring the pH back up to 5.6
and after a couple of days the pH will stop moving.
You will have the solution buffered
with these three potassium molecules
and can reach a perfectly stable equilibrium.
When you add nutes to RO water, the nutes alone will probably lower the ph to around 5.6
If the ph drops below 5.6 after you have added new nutes to RO water,
use .1ml/gl Barricade to buffer the ph back up to 5.6.
Solutions with RO or distilled water
will require the use of an eye dropper to maintain pH.
Measure pH between each drop,
until you are familiar with your solutions requirements.
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These are the pH rules for tapwater,
or water over 50ppm and/or initial pH of near 8.
After you add nutes to your water,
the pH should be close to 5.6.
If your water is very hard, over 200ppm,
then you will need to add pH down
(Phosphoric acid, or Nitric acid)
to achieve 5.6.
In a few hours,
as the buffers absorbs the acids,
the pH will move up,
back to near the original pH of the water.
So, you will need to continue to add pH down,
at least twice a day,
to re-establish the pH back at 5.6
After doing this for a few days,
the pH will become stable for a few hours,
maybe even for a day or so,
and then the pH will fall below 5.6 without adding any pH down.
When the pH falls without you adding pH down,
you have met the pH rule.
This is when it is time to change the nutes,
even if you have not met the Add Back Rule
For some nutes,
it is best if you always let the pH move from low to high,
and then you adjust it back down,
while other nutes will react in the opposite way,
depending on whether the mfg decided to buffer the formula or not.
Try to never allow the pH lower than 5.2 or higher than 6.2,
ideally you will maintain 5.6,
but in reality you will probably drift between 5.2 and 6.0
The time that this sequence takes will vary with the plant size,
the amount of water the plant is consuming/transpiring,
and the concentrtation of the nute solution (ppm/nute load).
If you are growing with tapwater,
the pH rule is the best method to determine when to change the nutes.
It can be as long as 10 days, and as short as 4 days.
If you must use tapwater,
It is highly recommended to use a Hard Water nutrient.
Your rez volume, the phase of your grow, and the type of nutes you have
will determine how often you need to adjust the pH.
Your job is to maintain the pH,
and change out the nutes at the appropriate time.
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