You're standing in front of a shelf of nutrient bottles at your local hydro shop with no idea where to start. There's a two-part A+B, something labelled "coco specific," a three-part Flora Series, and one bottle promising to do it all.
Quick answer: Hydroponic nutrients are water-soluble mineral salts. They supply the 17 elements plants need, in a form roots take up straight away. For a first grow you need one complete base nutrient, held at pH 5.5 to 6.5 and an EC of 0.8 to 1.6 for most leafy crops.
That question — what do my plants actually need — is the one we hear more than any other from first-time growers at LaNiTex Hydro Garden. And the answer matters more here than in any other growing method. In soil, the ground stores nutrients and releases them slowly through microbial activity. In water, there are no microbes doing that work. So your plants rely on the mix you make up for nearly everything. Some growers do run beneficial microbes in the root zone. But nothing in a standard setup turns organic matter into plant food the way soil does. That means the formula, the pH and the strength all have to be right from day one. Get the product wrong and the first grow often fails.
So this guide covers hydroponic nutrients for beginners from the start: what hydroponic fertiliser is, how macronutrients and micronutrients work together, why pH and EC are the two numbers you check daily, and how to pick the right feed for your system. No chemistry degree required.
Why hydroponic nutrients aren't the same as garden fertiliser
Standard garden fertilisers feed soil, not plants. They rely on bacteria and fungi in the growing medium to break organic matter into forms roots can absorb. That process takes time. And in garden beds it works beautifully. But a hydroponic system has no soil and no microbial workforce, so the conversion never happens.
Hydroponic nutrients are fully water-soluble mineral salts. Many products also carry chelated trace elements. That means the minerals are bonded to organic molecules, which keeps them stable in water instead of clinging to particles and dropping out. Not every product is chelated, though. So when you mix a proper hydroponic feed, each element is ready for roots to take up. Nothing has to break down first.
Using garden fertiliser in a hydroponic setup causes real problems. For example, undissolved particles clog pumps and block root zones. Also, organic formulas bring bacteria and algae into your reservoir. Soil pH amendments and slow-release products are not made for inert water. They can upset hydroponic pH, or leave material that never dissolves. So unless the label says hydroponics, leave it on the shelf.
The hydroponic nutrients your plants actually need
Plants need seventeen essential elements to complete their life cycle. And your feed has to supply most of them. They fall into two groups: macronutrients, which plants use in large amounts, and micronutrients, needed in traces but just as critical.
Macronutrients: nitrogen, phosphorus, and potassium
Nitrogen drives leafy growth. And phosphorus supports roots, flowering and fruit set. Potassium governs plant strength, water movement and ripening. In the vegetative stage, plants want proportionally more nitrogen. That's often written as something like a 3-1-2 N-P-K ratio. Then flowering begins and the balance shifts toward phosphorus and potassium, roughly the other way around. Treat those figures as a rule of thumb, not a formula. The right balance depends on the crop, the variety and your conditions. So most two-part systems split "Grow" and "Bloom" across separate bottles rather than using one product for the whole cycle.
Calcium and magnesium get called secondary macronutrients. But they're far from optional. Calcium builds strong cell walls and is critical for healthy new growth. A shortage shows up as twisted, distorted or dead-tipped leaves on your newest shoots. Magnesium sits at the centre of chlorophyll production. A shortage there causes interveinal chlorosis on older leaves: the tissue between the veins yellows while the veins stay green. And sulphur rounds out the group.
Micronutrients: small amounts, serious consequences
Iron, manganese, zinc, copper, boron and molybdenum are the micronutrients your plants need in tiny amounts. But a complete hydroponic mix supplies all of them. That's one advantage hydroponic fertiliser holds over many soil products. In soil, some micronutrients are assumed to be there already. In hydroponics your feed is the only source, so a good product leaves nothing out.
Shortages of single micronutrients also show up faster than they would in soil. For example, iron shortage turns the youngest leaves yellow or almost white while the veins stay green. And boron shortage produces fleshy, distorted roots and misshapen new growth. Most micronutrient problems appear on new leaves rather than old ones. So that's the first place to look when something seems off.
Hydroponic nutrient deficiency symptoms at a glance
Most beginner problems look alike at first. This table narrows it down by where the symptom shows and what it looks like.
| What you see | Likely cause | First thing to check |
|---|---|---|
| Older, lower leaves yellow between the veins while the veins stay green | Magnesium | Feed strength, and whether your product includes magnesium |
| Youngest leaves yellow or almost white, veins still green | Iron | pH first — iron availability drops sharply above 6.5, long before the feed runs out |
| New shoots twisted, distorted, or with dead tips | Calcium | pH at the low end, and whether coco is binding calcium |
| Whole plant pale and growing slowly | Nitrogen, or simply an EC that is too low | EC reading before assuming a shortage |
| Leaf tips burnt and curling | Most often too much feed, not too little | EC first — dilute rather than add. Heat and low humidity can burn tips too |
| Fleshy, distorted roots and misshapen new growth | Boron | Whether your product is a complete mix with trace elements |
One rule saves a lot of wasted effort: check pH before you change anything else. A locked-out nutrient and a missing one look identical on the leaf. But only one of them is fixed by adding more feed.
One-part, two-part, and coco-specific hydroponic nutrients explained
The format of your hydroponic nutrients decides how you mix them, how strong they can be, and whether they suit your medium. Pick the wrong format and you can see shortage symptoms even while following the label. That's a common beginner trap.
One-part nutrients: the simplest starting point
A one-part feed puts everything in a single bottle. You measure it, add it to the reservoir, and you're done. Also, it's the most beginner-friendly format, and it works well for leafy greens and herbs in simple systems. Growth Technology's Ionic range is a widely available Australian example. It's pH-buffered, so it's more forgiving while you find your feet. Even so, buy a pH and EC meter before your first mix rather than after. Source water varies from suburb to suburb, and a buffered product can't tell you where your tap water started. The trade-off is strength: one-part formulas are less concentrated than two-part ones. Calcium and phosphate react when stored together at high strength and drop out of solution. For a first grow of herbs or salad greens, that rarely matters.
Two-part A+B systems and the one mixing rule you can't break
Two-part systems fix the calcium-phosphate problem by splitting the formula across two bottles. Part A carries the calcium and nitrogen. And Part B carries the phosphates, potassium and micronutrients. Kept apart as concentrate, they're stable. But mixed into water, they make a complete, high-strength feed. Canna's Aqua range is a widely available Australian example of a true A+B system. Note that General Hydroponics' Flora Series is not a two-part system at all, despite often being mentioned in the same breath. It's a three-part range — FloraGro, FloraMicro and FloraBloom — that you mix in different ratios as the plant moves through its stages. Both approaches work. They just solve different problems. A+B solves the storage chemistry. A three-part range gives you finer control as the plant changes. For a closer look at a two-part product in practice, see our breakdown of the HY-GEN Hydro Growth two-part nutrient.
Here's the rule you cannot break: never mix Part A and Part B concentrates together. Always fill the reservoir with water first. Then add Part A and stir until it's fully dissolved. Then add Part B and stir again. Mix the concentrates directly and you create an insoluble calcium-phosphate residue. That blocks lines, clogs pumps and locks nutrients away from your plants. The order of addition is not a suggestion.
In practice, mixing a batch runs in this order:
- Fill the reservoir with water. Let it sit a few hours if it is straight from the tap.
- Measure the baseline EC of the plain water and note it down.
- Add Part A at the dose on the label, then stir until it is fully dissolved.
- Add Part B, then stir again. Never combine A and B in a jug first.
- Re-check the EC against your target for the stage, allowing for that baseline.
- Adjust the pH last, once everything else is in. Adding feed after adjusting pH will move it again.
Hydroponic nutrients for coco: why coco needs different ratios
Coco coir is not an inert medium. It binds potassium hard, and it holds calcium differently from other substrates. That makes both elements briefly unavailable to roots. So coco products are built with more calcium and potassium to cover the gap. Use a standard hydroponic mix in coco without adjusting, and shortage symptoms often follow in an otherwise well-run system. Brands like Canna Coco and Hy-Gen's Coco line are made for this, and they save you working the adjustments out by hand.
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Join the newsletter →EC and pH for hydroponics: the two numbers that determine whether your plants actually eat
You can mix the most carefully built feed on the market. But it becomes useless if your pH sits outside the right range. This is nutrient lockout, and it's one of the most misread problems in beginner hydroponics. The plants look starved. Then adding more feed makes things worse, because the issue is access, not amount.
Start with your water, not the bottle
Before you add a millilitre of feed, test what's already in your water. Tap water carries dissolved minerals of its own. That baseline shows on your EC meter as a reading above zero. Say your tap water reads 0.3 mS/cm and your lettuce target is 1.0. Then you only have 0.7 of headroom to work with. So measure the baseline first and subtract it from the target. Otherwise you will overfeed without realising.
Water alkalinity matters too, and it isn't the same thing as pH. Alkalinity measures how hard your water resists a pH change. That's why some growers find their pH creeping back up within hours of adjusting it. University of Missouri Extension notes that alkalinity can't be read from a pH meter at all. High pH does not automatically mean high alkalinity, and the reverse holds too. So if your pH will not hold, alkalinity is the usual culprit.
Plenty of Australian tap water is usable once it has stood a few hours, which lets free chlorine gas off. But check what your utility actually adds first. Many Australian networks dose chloramine instead, and chloramine does not gas off by standing. For a chloraminated supply, a carbon filter is the practical fix. Reverse osmosis or distilled water is worth the cost only when your source water is genuinely high in dissolved solids — roughly above 0.8 mS/cm from the tap. For everyone else it's an unnecessary expense.
The pH range your system needs to stay within
Most hydroponic systems do best between 5.5 and 6.5. The sweet spot sits at 5.8 to 6.2. Outside that range, specific nutrients stop being available. Iron gets hard to absorb above pH 6.5, because it drops out of solution as the water turns alkaline. Chelated iron holds on longer than the unchelated form, so a good product buys you margin. But that's no licence to let pH drift. Calcium access also falls off below the low end, around pH 5.5 to 5.8. So check and adjust pH daily, especially in small reservoirs where it moves faster. A basic digital pH meter is one of the most useful tools you can own. Look for a combined pen that reads pH, EC, TDS and temperature. Then one tool covers every number this guide asks you to check.
EC targets by growth stage and what they mean
EC, or electrical conductivity, tells you how strong your feed is. Higher EC means more dissolved salts. As a starting point, seedlings sit low at 0.4 to 0.8. Then vegetative plants take roughly 1.0 to 1.6. Heavy feeders in full flower can push past 2.0. Treat these as opening figures rather than fixed rules, since published tables vary and the right number depends on your crop and conditions. For example, lettuce and leafy greens prefer an EC of 0.8 to 1.4 and pH around 5.5 to 6.5. Also, basil sits comfortably at 1.0 to 1.6. Tomatoes feed harder and handle 2.0 to 3.0 while fruiting. Starting low and climbing gradually is always the safer approach.
You will also see feed strength written as PPM, or parts per million, rather than EC. The two are not interchangeable unless you know the scale. PPM meters convert an EC reading using either the 500 scale, common in North America, or the 700 scale. So the same liquid can read 700 ppm on one meter and 980 ppm on another. If a feed chart gives a PPM figure without naming the scale, that number is close to meaningless. EC in mS/cm avoids the problem, which is why most Australian guides use it.
Push EC too high and plants get salt stress. Then you'll see leaf tips burn and curl. Too low and they slowly starve, showing the same pale, slow growth as a nitrogen shortage. So a digital EC meter takes the guesswork out of feeding. Because a combined pen reads EC as well as pH, one device covers both numbers.
Feeding hydroponic nutrients: DWC, NFT, and coco
DWC nutrients and NFT: keeping the reservoir on track
In deep water culture and nutrient film technique, there's no medium to buffer the feed. Your pH and EC readings reflect exactly what the roots sit in. So consistency matters more than it does in soil-adjacent media. Mix a fresh batch of nutrient solution every one to two weeks, or sooner if EC drops as plants feed. Then top up between changes with plain water rather than more feed. Water evaporates but the salts stay behind, and the mix slowly concentrates to levels that stress your plants.
Keep the whole reservoir in one enclosed unit on your bench. The tank, pump and full-spectrum LED are built in, so there is no rig to assemble. You supply the nutrient and the seeds.
Start your first grow →Personally tested at home on the Sunshine Coast before listing.
Reservoir temperature: the number most beginners never check
Roots need oxygen as much as they need feed. And warm water simply cannot hold much of it. So aim to keep the nutrient solution between 18 and 22 degrees Celsius. University of Missouri Extension puts the optimum dissolved oxygen level above 6 ppm. It also notes that warm water has a hard ceiling on how much oxygen it can hold. At 35 degrees Celsius that ceiling is about 6.85 ppm, and no amount of extra air will lift the water above it. Aeration still helps, because most reservoirs sit below their ceiling. But it cannot rescue a reservoir that is simply too warm. Cooling the water is the fix.
This matters more in Queensland than in most places. A reservoir in a warm room through a subtropical summer drifts well past that range. Then the symptoms get misread. Growth slows, plants wilt in the afternoon, and the roots turn brown and slimy. Growers usually reach for more feed when the real problem is roots that are suffocating. So keep the reservoir out of direct sun, and insulate the tank if you need to. Top up with cool water, not water that has been sitting in a hot hose.
Coco coir: why it needs a different feeding rhythm
Coco usually needs watering daily, and often more than once a day in warm weather. Frequency depends on pot size, plant size and your climate. For example, a small pot in a hot room dries out far faster than a large one indoors. Aim for enough liquid to create 10 to 30 percent runoff from the base of the pot. That runoff stops salt building up in the medium over time. A coco feed schedule is more hands-on than DWC. But it gives you better visibility into the root zone. So if runoff EC climbs well above your input EC, flush with plain water before the next regular feed.
Getting started without the guesswork
New growers often stall at the nutrient stage for one simple reason. They don't know which hydroponic nutrients to buy or how much to use. And matching a brand and formula to a system you don't yet understand is harder than it sounds, especially given the range on the Australian market.
LaNiTex Hydro Garden's systems take the setup guesswork off the table. Each kit arrives with the growing hardware included — planting sponges, cups and covers. And the manual walks you through mixing a standard two-part A+B feed step by step. The nutrient itself is sold separately, and that's deliberate. You can use any quality hydroponic nutrient from any Australian supplier, so you're never locked into proprietary pods or a single brand.
One thing you can safely ignore for now: additives. Walk into any hydro shop and you'll find shelves of Cal-Mag, silica, root stimulants, enzymes and bloom boosters. But a complete base nutrient already holds everything a plant needs. For a first grow of herbs or leafy greens it is genuinely all you need. Additives solve specific, diagnosed problems. For example, Cal-Mag helps when coco or RO water has stripped calcium and magnesium, and silica suits heavy fruiting crops. Buy them before you have a problem to solve and you just add variables to a system you're still learning to read.
For growers sourcing hydroponic nutrients separately, entry-level options like Ionic's single-bottle grow and bloom products are widely available and easy to use. Growth Technology's Vegetable Focus and General Hydroponics' Flora Series are both reliable starting points. Budget between AUD $60 and $150 a bottle, depending on the size you buy. Also buy in 5L containers where possible, since the cost per litre drops considerably against 1L bottles.
The bench-top workhorse
Everything this guide asks you to control, in one enclosed bench-top unit: sealed tank, pump and full-spectrum LED. You choose the nutrient and hold the pH and EC targets above.
Set up your first system →Personally tested at home on the Sunshine Coast before listing.
Outgrown the bench? The V5.2-A Tower runs the same routine across 72 planting sites, floor-standing with full-spectrum LED. Same nutrients, same two numbers to watch.
Scale up your grow →Personally tested at home on the Sunshine Coast before listing.
Common questions about hydroponic nutrients
What are hydroponic nutrients made of?
They are water-soluble mineral salts. Nitrates, phosphates, sulphates and potassium compounds supply the macronutrients. The trace elements are usually chelated, so they stay dissolved instead of settling out. These are the same ions a plant takes up through its roots in soil. The difference is what has to happen first. In soil, microbes break organic matter down into those ions. In a hydroponic feed they are already there.
Do hydroponic nutrients expire?
Sealed concentrate keeps a long time in a cool, dark spot. Heat and sunlight degrade it. So a shed through a Queensland summer is the worst place for it. Check before use: separation, crystals or a colour change mean the chemistry has shifted, and the label dose is no longer reliable. Mixed feed is different. Once it is in water it starts changing straight away. That means the reservoir gets a fresh batch every week or two.
Are hydroponic nutrients safe, or just synthetic chemicals?
The salts in a hydroponic bottle are refined into a purer, more consistent form. But chemically they deliver the same ions a plant would absorb from a compost-rich garden bed. A plant has no way of telling the difference. Used at the label rate, they are fine for food crops, and the produce is no less safe to eat than soil-grown. What does cause problems is overfeeding. That stresses the plant and wastes nutrient.
Are hydroponic nutrients expensive?
Not particularly, once you see how far a bottle goes. Budget roughly AUD $60 to $150 a bottle, depending on the size you buy. Also buy in 5L containers where you can. The cost per litre drops considerably against 1L bottles.
Start simple, adjust as you go
Hydroponic nutrients aren't complicated once you have the framework. Plants need macronutrients for structure and energy, and micronutrients for specific jobs. Then a stable feed at the right pH and EC makes it all available. The format you choose — one-part, two-part or coco-specific — follows your system and medium, not personal taste.
So before you buy anything, match your product to your system type. Then get a basic pH and EC meter. Those two tools tell you more about your system than anything else you can buy. Check both numbers daily, stay in the target ranges for your crops, and adjust gradually. That discipline alone separates growers who succeed from those who start over.
If you're setting up a first system and want the feeding routine explained step by step, a LaNiTex Hydro Garden system is a straightforward place to start. And every kit ships with a manual covering nutrient mixing from day one. The Smart Indoor Hydroponic Tower V5.2-A is the flagship for leafy greens and herbs. And the Grow Box – Smart Hydro Garden is the compact bench-top option. Browse the full range of indoor hydroponic systems, or contact us directly if you're not sure which suits your space.
