What this board covers
Use this board for questions about CANNA® products. CANNA® is a fertiliser brand that makes a separate nutrient line for each type of growing medium.
CANNA has three base lines: Terra, Coco and Aqua. A base line is a complete fertiliser that can feed the plant by itself. Terra is for peat-based potting mixes. Coco is for coco coir, which is shredded coconut husk. Aqua is for recirculating hydroponic systems. In these systems the nutrient solution drains back to the tank and is pumped to the plants again.
CANNA also makes additives. These are optional products that you add to a base line. This board also covers CANNA’s feed charts and how they work when your water is harder or softer than the water the chart was written for.
General feeding questions that are not about one brand belong in the General Nutrients board. Before you post here, check which base line you use and which medium your plants grow in. Then you can ask the question in the right place.
Why CANNA makes a separate line for each growing medium
Some brands sell one bottle and change the dose for each medium. CANNA does not. It makes a different formula for each growing medium (substrate), because each medium holds water and nutrients differently.
The CANNA name is on all three bottles, but the formulas inside are different. Terra, Coco and Aqua contain different chemistry. A dose that works in a Coco thread may not work for a grower using Terra.
Put the line name (Terra, Coco or Aqua) in your thread title. Readers can then compare your results with growers who use the same line.
Why Coco and Aqua come as two bottles, A and B
Coco and Aqua each come as two bottles, marked A and B. They are split because calcium salts and sulphate salts cannot stay dissolved together in a concentrate.
When the two meet in strong form, they precipitate. This means they react and form a solid that settles out of the liquid. The solid is gypsum (calcium sulphate), a white, chalky deposit. Roots cannot take up nutrients that are locked inside gypsum.
So if you pour undiluted A and B into the same jug, the plant gets neither the calcium nor the sulphate. The two parts are meant to meet only after each one is diluted in the full volume of water.
How to mix:
- Fill the tank with the full volume of water first.
- Add A and stir well.
- Add B and stir well.
- Use a separate measuring cup or syringe for each bottle, or rinse it between bottles.
This keeps the two concentrates apart until each one is diluted.
The feed chart assumes a water and a medium you may not have
A feed chart is the brand’s table of how much of each product to add to the water at each stage of growth. Every chart is written for an expected water source and an expected growing medium. If your water or medium is different, the same dose gives a different result.
The most common problem is hard water. Hard water already contains a lot of dissolved calcium and magnesium. The chart dose also supplies calcium and magnesium. If you add the full dose to hard water, the total ends up higher than the chart intended.
This means you can overfeed even when you follow the chart exactly. Overfeeding can show up as nutrient burn. Soft water has the opposite problem. It contains very little dissolved mineral, so the chart is wrong in the other direction.
Measure the EC of your plain water before you add anything. EC (electrical conductivity) is a meter reading that shows how much dissolved salt is in the water. Measure again after mixing. Many charts give a target EC for the finished mix. Read the note on your CANNA chart, because versions differ. Some CANNA line sheets say to add the EC of your tap water to the recommended EC. Some CANNA Australia schedules instead give a total EC that assumes your water starts at 0.4 mS/cm (0.2 mS/cm for Aqua), raised with CALMAG if needed. If the chart gives only the added EC, add your water’s own EC to the chart figure before you compare.
Translator’s note: water in Thailand and Southeast Asia
Water in the region varies a lot. Tap water can differ from one district to the next. Well water that rises through limestone can be very hard. Rainwater is very soft. So is water from a reverse osmosis (RO) filter, which removes almost all dissolved minerals.
A feed chart cannot know what comes out of your tap or well. Measuring is the only way to find out. Measure your water once in the dry season and once in the rainy season. Measure again whenever you change source. This shows whether your water changes enough to need a different dose.
You might consider RO water in two cases. The first is when your plain water EC is so high that the chart dose pushes the finished mix well above the chart’s target. The second is when your well water leaves white scale on pipes and drippers. RO gives you a known starting point.
RO has a catch, though. RO water contains no calcium or magnesium at all. Too much calcium and magnesium can turn into too little. For soft or RO water, CANNA recommends CANNA CALMAG Agent to raise the water to an EC of about 0.4 before feeding. CANNA also says the pH of a solution with CALMAG Agent first drops and then rises over 24–48 hours, so wait before you adjust pH.
CANNA sells some of its other lines, such as CANNA Hydro and CANNA Substra, in separate versions for hard water and soft water. A UK retailer describes Aqua Vega and Flores as made for mid-range water hardness. Ask your supplier in Thailand which version your bottle is.
Test any change on a small batch first. Mix one tank at a reduced dose, measure it, and feed a few plants. Compare them with the rest before you change your whole feeding programme.
What to post with your question
Disagreements in threads often start because nobody knows the water or the medium. Post these readings with your question:
- Water source: tap, well, rain, RO, or a mix. This tells readers what minerals to expect.
- EC of your plain water, with the unit: mS/cm, µS/cm or ppm. If you use ppm, say which ppm scale your meter uses. Meters on different ppm scales show different numbers for the same water.
- pH of your plain water. This shows how much pH adjustment the mix needs.
- Line, medium and chart week: for example, “Coco A and B in coco coir, week 3 of flower.” Readers then compare your results with the right chart.
- Dose used in ml per litre, and the EC and pH of the finished mix. This shows whether you are above or below the chart.
- Runoff EC, if you measure it. Runoff is the water that drains out of the pot. It shows whether salts are building up in the medium.
- Additives used, and their doses. This helps readers rule out an additive as the cause.
Calibrate your meter before you take these readings. If the meter is not calibrated, every comparison in the thread will be wrong.
Rhizotonic, Cannazym and the Boost products are additives, not a base
Rhizotonic, Cannazym and the Boost products are added to a complete base line. None of them is a base itself, so none of them can replace Terra, Coco or Aqua.
- Rhizotonic: CANNA describes it as an algae-based root stimulator.
- Cannazym: an enzyme product. CANNA says it speeds up the breakdown of dead root material in the medium.
- Boost products: CANNA labels CANNABOOST Accelerator and CANNA PK 13/14 as boosters. PK 13/14 is used for one week at a time during flowering.
Get the base line and the dose right first. Then add one additive at a time and write down what changes. If a problem appears, you will know which bottle caused it.
Translator’s note: buying and storing CANNA bottles in Thailand
Ask an authorized distributor in Thailand where to buy. You can also ask other growers about their experience in the Equipment and Supplies board. Bottles from unofficial sellers may be fake, out of date, or stored in hot sun.
Before you buy, check the batch or production date and the seal. Store bottles out of direct sun and away from heat. Outdoor air in Thailand often reaches 30–35 °C, and closed sheds and vehicles can get hotter.
Fertilisers in Thailand fall under the Fertilizer Act B.E. 2518 (1975), as amended by the Fertilizer Act (No. 2) B.E. 2550 (2007). Topic 1464 explains how to check that a fertiliser is legally on sale in Thailand.
Where to start
- Read the CANNA fertiliser guide linked at the top of this post. It goes through Terra, Coco, Aqua and the Boost products one by one.
- If you plan to spray Rhizotonic on leaves, read the foliar spraying topic linked in the additives section above.
- Measure the EC and pH of your plain water. Then open a thread in this board and post the readings from the list above with your question.
If something here does not match your experience with CANNA in Thai water, post your readings below this topic so other growers can compare.