by Nebula Haze
For many cannabis growers, choosing nutrients can be a pretty confusing topic. Tons of companies to wade through, and many companies have multiple nutrient lines, supplements, additives, and more. Once you’re through with that, you still have to figure out how much and how often to feed your marijuana plants for the best growth and yields. So what are the best cannabis nutrients, and how do you use them? Luckily, almost any cannabis-specific nutrient line can grow great cannabis (what to look for in the best cannabis nutrients), but some companies empty your wallet and/or give you much more work than needed.
For around $35, the Flora trio gives pro-level results in the cannabis grow room. For example, I grew these weed plants from seed to harvest with only the three bottles of Flora trio as nutrients.
Why I like the General Hydroponics Flora trio as a marijuana fertilizer
- Excellent Results – Cannabis plants grow fast and healthy when getting the Flora Trio using the schedules below. Flora-grown plants produce outstanding yields, smells, and bud potency. Buds are smooth to smoke.
- Price – Some cannabis nutrient systems cost more than your equipment. I’ve seen a grower pay nearly $1000 for a high-end cannabis nutrient system on her first grow. The General Hydroponics Flora trio is everything a plant needs from seed to harvest, and the quart-size trio costs ~$35 (typically between $30-40). For most home growers, these bottles last multiple grows. The Flora trio is the least expensive of the great cannabis nutrient systems.
- Storage – Considering the bottles can make hundreds of gallons of water, it’s important they store for a long time. General Hydroponics has its quality assurance on lock. The bottles never leak and come with tight seals. The nutrients themselves are completely clear, never cloudy, never crystalize, etc.
- Flexible – General Hydroponics Flora trio works great for any grow medium including soil, coco, or hydro. Many nutrient systems can only be used for soil, or only for hydro, etc. It’s not to have more flexibility to experiment with different grow media at the same time, or try something new for your next grow, without having to switch nutrients.
- Simple – Flora trio is simple. You just follow the schedule below and you don’t need to worry about the nutrient portion of your grow. Note: It is simple but not the easiest system because you still have to use 3 bottles. The award for “easiest cannabis nutrient system” may belong to Dyna-Gro Foliage Pro and Bloom, since you only use one bottle at a time.
Note: I have no affiliation with General Hydroponics, I just like their nutrients for growing weed.
Today, I’m going to show you how I use General Hydroponics Flora Trio + (optionally) CaliMagic as cannabis nutrients. If you’ve been stuck figuring out how to feed your cannabis plants high-quality nutrients while keeping the cost low, this is the answer.
These cannabis buds were grown using only the Flora trio, without any other supplements.
Here were the cannabis plants that bud came from (here are more details about that cannabis setup)
Important: Flora trio is a great nutrient system, but as long as your cannabis plant gets all necessary nutrients, the genetics, care, and growing environment affect bud quality more than the particular nutrient brand.
What is the General Hydroponics Flora Trio?
Note: Don’t let the name fool you, the Flora Trio is great for soil, coco coir, hydro, or almost any growing medium.
General Hydroponics is the name of a company that makes nutrients, potting mixes, and pH adjustment kits among many other things. They have been producing a nutrient line called the Flora Trio since the 1970s, and I’ve used it on and off since I started growing in 2008. I keep trying other nutrient lines for growing cannabis, and then coming back to the Flora series.
The Flora Trio is three bottles (Grow, Micro, and Bloom) that are combined in different ratios depending on your plant’s stage of maturity.
A common extra supplement is CaliMagic, which adds extra Cal-Mag (Calcium and Magnesium). CaliMagic, which supports optimal cannabis growth and may help prevent calcium deficiencies (most common when growing in coco or using filtered water). However, the regular Flora series has plenty of Calcium and Magnesium, so most growers will have success with just the trio. Especially if using tap water as opposed to filtered water, since tap water also typically contains some amount of calcium and magnesium.
General Hydroponics (like most if not all nutrient companies) try to sell their base nutrients with a bunch of other supplements, but using just the Flora trio’s three bottles (and optionally CaliMagic) will do everything you need in addition to saving money. Let me show you how to do it today!
More cannabis buds I’ve grown with Flora trio
Here were the cannabis plants those buds came from.
Alright, now let’s get to how to actually use the stuff!
How I Use GH Flora Trio For Cannabis (Custom Schedule)
You may want to hear something a lot more fancy, but the easiest way to use General Hydroponics is…
Follow the bottle at half-strength. Simple as that!
Yep, this is the easiest method and works extremely well for cannabis plants. In my experience, this simple formula works just as good as any complicated schedule. Scroll down for pictures of plants so you can tell when/if your cannabis plants need more or less nutrients.
Just look at the label on the bottle and follow at 1/2 strength for the vegetative and flowering stage. Only increase to 3/4 or full strength if plants look pale or lime green.
Here is a closeup of the directions. Follow this at 1/2 strength and get great results growing weed.
If you can’t see the picture, or just want it written out, this is what I do (this works well in soil, coco, or hydro).
Seedlings
- 1/4 tsp per gallon of each bottle (this is the only suggestion I used at full strength)
Vegetative
- 1/2 tsp per gallon from each bottle
Transition – give this for 2 weeks after your plant starts making buds
- 1 tsp per gallon from each bottle (if you see burnt tips, go back to 3/4 or 1/2 tsp per gallon)
Flowering – if you get confused, just remember to use 1/2 strength of what’s recommended on the bottle for “Blooming and Ripening”
- Micro: 1 tsp per gallon
- Grow – 1/2 tsp per gallon
- Bloom 1 1/2 tsp per gallon
Note: 1 tsp = 5 ml
Soil
Here’s a chart demonstrating how I use the Flora Trio in grow cannabis in a drain-to-waste medium like soil or composted soil:
Coco (or other soilless medium)
Here’s a chart demonstrating how I use the Flora Trio to grow cannabis drain-to-waste mediums like coco coir/perlite, vermiculite/perlite etc.:
Supplemental Instructions:
- Add nutrients to water (Micro first)
- Adust pH of nutrient water by using pH Up or pH Down
- Hydro/Coco: 5.5 – 6.5 pH | Soil : 6.0 – 7.0 pH
- Give water to plants and remove any runoff
- Adjust nutrient strength as needed…
- More nutrients for pale plants with yellow lower leaves
- Less nutrients for dark-green plants with nutrient burn
Photoperiod Notes:
- Repeat Week 4 until plant is half final desired height
- Initiate flowering stage with a 12/12 light schedule
- Repeat Week 9 for a longer flowering stage
Autoflowering Notes:
- Repeat Week 4 until you see buds, then start Week 5 (Transition)
Soil cannabis plants (autoflowering) grown with Flora trio
Soil bud closeup
Coco plants grown with Flora trio
Coco buds closeup
Deep Water Culture (Recirculating Nutrient Reservoir) Schedule for Hydroponics (DWC)
And here’s a chart demonstrating how I use the Flora Trio in recirculating systems like DWC/Bubbleponic, Ebb & Flow, etc.:
Supplemental Instructions:
- Add nutrients to water (Micro first)
- Adust pH of nutrient water by using pH Up or pH Down
- Hydro/DWC: 5.5 – 6.5 pH
- Top off reservoir often to maintain a 2″ air gap
- Adjust nutrient strength as needed…
- More nutrients for pale plants with yellow lower leaves
- Less nutrients for dark-green plants with nutrient burn
Photoperiod Notes:
- Repeat Week 4 until plant is half final desired height
- Initiate flowering stage with a 12/12 light schedule
- Repeat Week 9 for a longer flowering stage
Autoflowering Notes:
- Repeat Week 4 until you see buds, then start Week 5 (Transition)
Hydroponic cannabis grows with Flora trio + CaliMagic
Example of a hydro-grown cannabis bud
What if you see a nutrient deficiency with the General Hydroponics Flora Trio following this schedule?
I recommend starting with the amounts listed above. If your cannabis plant shows signs of deficiencies, check the pH first as this is the most likely reason to see nutrient deficiencies if you’re using a good cannabis nutrient system like General Hydroponics.
Learn how to check pH to prevent nutrient deficiencies!
If you’ve confirmed your pH is in the correct range and you’re still seeing nutrient deficiencies, increase the amount of nutrients you’re giving your plants. Make sure to treat the amount recommended by General Hydroponics (see below) as an absolute maximum; giving full strength tends to end in nutrient burn.
When to increase nutrient levels
The plant on the left is pale and the lower leaves are turning yellow and falling off – this means it needs more nutrients. The plant on the right is a healthy green. If your plant looks like this, don’t change anything!
Increase nutrients when a plant appears pale but otherwise healthy.
When to lower nutrient levels
It is unlikely you’ll overburden your cannabis plants with the nutrient levels provided on this page, but some plants are particularly sensitive to nutrients. Here’s how to know if you need to lower your nutrient levels.
If you see burnt leaf tips all over, it means you’re giving too much nutrients and should pull back. The burnt tips won’t recover, but if you start giving the right amount of nutrients, they’ll stop spreading.
Dark green leaves are another sign you’re giving too much nutrients.
When the nutrient deficiency is caused by pH
If you’re using the General Hydroponics trio as directed and you see spots or markings, bronze patches, and other deficiencies not shown above, the problem is almost certainly caused by pH. That’s because nutrients take different forms depending on the pH at the roots, and some of these compounds are easier for your cannabis roots to absorb than others. If you maintain the pH that cannabis plants are adapted to, it ensures all the nutrients are easily available. If the pH is way too high or low at the roots, your plant can’t get access to almost any nutrients and will soon be covered in deficiencies.
The following nutrient deficiencies are the result of incorrect pH. Even if you’re giving perfect nutrients, you will still see deficiencies if the pH is too high or low at the roots.
Notice how there are brown spots and leaves aren’t just yellow but a reddish-orange color. When you see these symptoms, it is usually caused by incorrect pH at the roots.
If no bugs are present, brown splotches are typically the result of incorrect pH (or sometimes overwatering).
These brown splotches were the result of incorrect pH at the roots.
Another cannabis leaf symptom caused by incorrect pH.
Incorrect pH
Low pH in the flowering stage.
A different view of that same plant. This was due to low pH in the flowering stage.
Which cannabis nutrient deficiencies are caused by pH? [Picture Guide]
Those using coco coir and/or reverse osmosis water will want to add a calcium/magnesium (cal-mag) supplement to make up for the lack of it in your water. Growers using tap water often have enough calcium/magnesium in their water already, but it’s a good idea to add it if you know you live in an area with soft (more pure) water.
What does the official General Hydroponics schedule say for Flora trio?
As far as other supplements, you’ll see that the charts below from GH recommend a few of them. While I’m sure they have their merits, I don’t recommend using any of the ones listed unless you’ve tried this line already and want to experiment. From my experience, I’m sure you’ll get the results you’re looking for without having to add even more bottles to your nutrient line-up.
Now for the standard instructions! (you know, the kind that happens to cost a ton of money with hard-to-quantify benefits)
How GH Tells You to Use It (with lots of supplements)
Here’s the chart from General Hydroponics for mediums like coco coir, soil, perlite, etc.:
And here’s their chart for recirculating systems like DWC, Ebb & Flow, etc.:
Personally, I’ve found the extra supplements and higher levels of nutrients recommended by General Hydroponics to be unnecessary. I get great results using the more simple and cannabis-specific nutrient levels recommended by my custom schedule!
Tips for Using the Flora Trio
Here are a few tips about this nutrient line that’ll save you some time and money!
- You can make nutrient water in advance and store it for up to a week. Some people store nutrient water for longer, but a single week is considered safe by General Hydroponics. Nutrient water lasts longer if the container is completely full (since there is no oxygen for bad microorganisms). After a container is partially empty, the water can get smelly if you seal it back up. Leave the top off in that case to get a little extra time.
- Store your nutrient bottles in a darkened area (no direct sunlight) with cool (but not freezing) temperatures. When stored properly, these nutrients can last for over 5 years even after they’ve been opened. If the nutrient solution looks clear (not cloudy or crystalized with stuff floating) and doesn’t smell different than when it was new, it’s likely still good to use.
- Try using a pipette to get Flora Micro out of the bottle. This way you avoid having to pour it, which can be a pain. Micro has a weird drippy consistency that makes it easy to spill while pouring. Another idea is to put Micro in a squeeze bottle.
- Using small amounts of nutrients not only makes it so you save a bit of money, but it makes your nutrient-water a lighter color. This in turn makes it easier to use drop-type pH test kits which are super cheap! A drop-type pH test kit can also last years when stored and used properly!
- I know it sounds like a no-brainer, but make sure you put down a towel before your pour nutrients! Two of the liquids are pretty tame, but Micro is wine-colored with an odd consistency!
Get the General Hydroponics Flora Trio Today!
Why GH Flora trio?
Let me start off by saying I have no stake of any sort in General Hydroponics. I don’t get paid by them or their companies or receive free products or anything like that. I just think they make awesome stuff. Now, on to why I recommend you give them a try if you haven’t already found a suitable nutrient line:
Cheap
GH Flora Trio tends to go for about $10-$14 per 32oz bottle, which comes out to $30-$42 for all three plus $20 for (optional) CaliMagic supplement. That doesn’t seem cheap until you factor in two things: you only use a small amount at a time, and the expiration date on the bottles is pretty far off. For a small personal garden, about $50 worth of nutrients can last for years. Just as importantly, the nutrients last for years even when opened as long as they’re properly stored.
It Works!
Many growers believe that the secret to getting medical-grade bud with the ‘magazine look’ is having the right nutrients. Believe it or not, all nutrient lines perform the same job: providing the elements your plant needs for healthy plant processes. The ways different nutrient lines provide these minerals can differ and the formulas they use can vary vastly (just like nutrient content varies in soil), but these changes aren’t what makes that envy-inspiring bud…it’s the care, a good environment, and a lot of light! With that in mind, the Flora Trio works exactly like it should in that it just gives your plants the minerals they need.
Simplicity
If you ignore the extra add-ons frequently sold with the Flora Trio, it becomes a simple, long-lasting solution to a seemingly complicated problem. The simplicity of the formula they use (dissolved salts) makes it last 5+ years after being opened when stored correctly, and only using three bottles makes it simpler to use than a full nutrient and supplement line.
Widely Available
The Flora trio is one of the most common nutrient lines made for plants like cannabis and is easily found online and at hydro stores.
Jump to…
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