Bunnings Fertilisers in Hydroponics Australia

Can You Use Bunnings Fertilisers in a Hydroponic System?

Every hydroponic grower has stood in the Bunnings garden aisle at some point and wondered whether Seasol, PowerFeed, Charlie Carp, Yates Thrive or Gogo Juice could replace a proper hydroponic nutrient. They're cheaper, they're available without a 40-minute drive to a hydro shop, and the marketing on the bottle sounds convincing enough. So can you actually use them in a recirculating hydro system?

The honest answer is more nuanced than a flat yes or no. Some of these products are genuinely fine in small doses if you know exactly what you're doing. Others create real problems that have nothing to do with brand loyalty and everything to do with how they're formulated. This guide breaks down what's actually in each product, what Australian growers report when they've tried them, and where the real risks are.

Seasol: A Seaweed Tonic, Not a Nutrient

Seasol is a seaweed-derived root tonic and plant stress reliever. It's not designed to feed a crop and was never marketed that way. The official product analysis confirms it, listing Nitrogen at 0.1%, Phosphorus at 0.01%, and Potassium at 1.5%, alongside trace elements including calcium, magnesium, iron, and boron.

What it does well is support root development and help plants recover from stress, transplant shock, or environmental setbacks, the same way it's used in soil gardens. Used this way in a hydro system in small amounts, it's a genuinely low-risk addition. Just don't reach for it expecting it to replace your base nutrient. That's not what it's built to do.

PowerFeed: Real Numbers, Real Limitations

PowerFeed is Seasol's fortified product, and unlike standard Seasol, it carries genuine nutrient content. Seasol's official analysis lists PowerFeed at Nitrogen 12%, Phosphorus 1.4%, and Potassium 7%, with calcium around 1,800mg/L.

That's a real NPK ratio, but look at the shape of it. High nitrogen, moderate potassium, very low phosphorus. It's a profile built for vegetative leaf growth on garden beds and lawns, not for a hydroponic crop moving into flowering or fruiting, where phosphorus demand rises significantly. Australian gardening forums discussing PowerFeed describe exactly this limitation: useful for general green growth, noticeably short on phosphorus when plants need to set flowers or fruit.

Charlie Carp: The Whole-Fish Problem

Charlie Carp is a hydrolysed whole-fish fertiliser, and its NPK sits around 10:1:6 depending on the specific product line. Like PowerFeed, the nitrogen and potassium are workable but phosphorus is thin.

The bigger issue with Charlie Carp in a hydroponic context isn't the NPK ratio. It's what the product physically is. Charlie Carp is made from whole fish, filtered down to just 100 microns according to their own published FAQ. That's coarse enough to leave real organic particulate matter in solution. In a soil garden bed, that organic matter breaks down into the soil and feeds beneficial microbes. In a recirculating hydroponic reservoir, that same particulate matter doesn't have anywhere to go. It settles in tubing, pump housings, and net pots, and it becomes exactly the kind of organic residue that feeds problems explained further down. If you're chasing real flowering and fruiting performance rather than working around a low-phosphorus garden fertiliser, Byron Bay Gold Flower A+B is in a different league entirely. It's Australian-made, purpose-built for serious yield and quality, and carries the correct phosphorus and potassium ratio for that stage without any of the guesswork.

Gogo Juice: A Living Biological Product

Gogo Juice is a liquid compost tea concentrate, built around a live microbial culture rather than a measured NPK ratio. It's marketed as a soil and root biology booster, and in garden beds that's exactly what it does. It introduces beneficial microbes into living soil.

In a sterile or semi-sterile hydroponic reservoir, that changes the equation. You're introducing a live biological culture into a system that doesn't have the soil ecology to balance it. The organic carbon source that feeds the microbes in Gogo Juice is the same type of organic load that creates conditions for less desirable organisms to take hold in a warm reservoir. It's not that Gogo Juice is a bad product. It was never designed for a hydroponic system, and used there it behaves unpredictably.

Yates Thrive: The Best NPK Numbers, With a Catch

Of every Bunnings product covered here, Yates Thrive actually has the most complete NPK profile for flowering and fruiting crops, with a ratio reported around 15:4:26. Solid nitrogen, genuinely useful phosphorus, and high potassium.

The catch is that Thrive is a synthetic salt-based fertiliser. It delivers nutrients as soluble mineral salts rather than the chelated, balanced mineral profile a hydroponic nutrient is built around, and it carries no calcium or magnesium supplementation, which most Australian tap water and growing media already run short on. In a recirculating system where the same solution is reused and topped up over days or weeks, salt-based fertilisers not built for hydro use are more prone to building up in ways that throw EC and individual nutrient ratios out of balance, even when the headline NPK numbers look reasonable. A dedicated 2-part system like Dutchfest Grow & Bloom A+B has calcium and magnesium built directly into the formula, removing that gap entirely rather than needing a separate supplement bolted on.

The nitrogen level is also worth flagging on its own. At 15% nitrogen, Thrive runs high for the later stages of many flowering crops, where nitrogen demand naturally drops off as plants shift energy into flower and fruit development. Continuing to feed a high-nitrogen product like Thrive into late flower can delay ripening and push plants to prioritise leafy growth over the flowers and fruit you're actually trying to produce.

Manutec: A Genuine Hydroponic Range, With Limits at the High End

Manutec is likely the second most searched Bunnings product after Yates Thrive for one simple reason: it's the only range at Bunnings actually labelled and sold as hydroponic fertiliser, not a garden product being repurposed. Manutec is an Australian-made line built specifically for hydroponic systems, sold as three separate products: Hydro Plus as a balanced all-rounder, Nitro Plus for leafy greens and herbs with elevated nitrogen, and NK Plus for fruiting and flowering crops with higher potassium and added calcium.

For leafy greens, herbs, and general vegetable growing, Manutec is a legitimate, well-formulated option. The NPK ratios are sound, calcium and the core trace elements are present, and growers comparing the actual numbers on forums have concluded they're genuinely workable for everyday hydroponic use.

Where it likely falls short is at the high end of flowering and fruiting crops with serious yield or quality expectations. Manutec doesn't advertise chelated micronutrients, which is the specific technology that keeps iron, manganese, and other trace elements available to the plant across a wider pH range. A leafy green crop with a short growth cycle and modest micronutrient demand can tolerate minor pH drift without much consequence. A flowering crop in its final weeks, drawing heavily on calcium and micronutrients during a short critical window, is far less forgiving of the same drift. This isn't a confirmed flaw, since Manutec doesn't publish chelation details either way, but it's a meaningful gap in what's disclosed compared to dedicated hydroponic nutrient brands that highlight chelation specifically because it matters at that stage.

The honest takeaway: Manutec is genuinely worth considering for leafy greens, herbs, and lower-demand vegetable crops where its NK Plus or Hydro Plus formulas line up reasonably well with what those plants need. For high-value flowering or fruiting crops where you're chasing maximum yield or quality, the lack of disclosed chelation is a real enough unknown that a dedicated hydroponic nutrient remains the safer choice. A simple complete system like GT Iconic Grow & Bloom covers the same full grow-to-flower cycle in one product, with the chelated micronutrient quality you'd expect from a dedicated hydroponic brand rather than an unknown.

If You're Going to Use Any of These Products in Hydro

If you do decide to experiment with any Bunnings product in a hydro reservoir rather than buying a dedicated hydroponic base, the single most important rule is to dose in small amounts and test EC after every addition, rather than following the bottle's recommended dose blind.

None of these products were formulated with hydroponic EC targets in mind, so there is no reliable dosing chart to follow. Add a small amount, mix thoroughly, test your reservoir EC with a proper meter such as the Bluelab Combo Meter, and only add more once you've confirmed where you've landed. Build up to your target EC in increments rather than guessing at a single dose and hoping it lands in range. This is genuinely the only safe way to use any of these products in a hydro system, and it takes more time and attention than simply following a hydroponic nutrient's feed chart.

Superthrive: Why Hydro Growers Are Split

Superthrive comes up constantly in indoor growing discussions as a vitamin and hormone additive, and the grower consensus on using it in hydroponic reservoirs is more divided, and more cautionary, than its popularity suggests.

Multiple experienced growers on cultivation forums report a consistent problem: leaving Superthrive in a hydroponic reservoir continuously leads to bacterial and algae blooms within two to three days. One grower described the water turning visibly slimed after repeated use in a DWC system. Others describe the same outcome and have stopped using it in hydro specifically because of this. The product itself isn't fraudulent. It does contain a genuine blend of vitamins and hormones, but the specific practice of dosing it into a standing hydroponic reservoir appears to be exactly what creates the contamination risk growers report.

Where Superthrive is used more cautiously and with less reported issue is as a single, one-off application during transplant shock or recovery, rather than an ongoing reservoir additive between every reservoir change. Even then, opinion among experienced growers is mixed, with some calling it genuinely useful for stress recovery and others dismissing it outright. If you're going to use it at all, a single dose applied directly rather than left sitting in your reservoir is the more cautious approach based on what growers actually report.

The Splash and Spill Risk Most Growers Don't Think About

There's a separate risk with organic, unrefined products like Charlie Carp and Gogo Juice that has nothing to do with what happens inside your reservoir. If you're hand-watering or mixing these products and any solution splashes onto the tent wall, the floor, or fabric surfaces inside an enclosed grow space, that residue becomes a real mould risk. This isn't theoretical. We've heard directly from growers who developed black mould in their grow space specifically after hand-watering Gogo Juice and splashing it on the tent walls.

Mould and grey mould (botrytis) spores are airborne and present in virtually every indoor environment. They need two things to establish: moisture and an organic food source. A sealed grow tent running standard indoor humidity already provides the moisture. An accidental splash of fish emulsion or live compost tea concentrate on a tent wall provides the organic food source mould spores need to take hold, in a way that a clean synthetic hydroponic nutrient simply doesn't. This is a small, specific risk rather than a reason to avoid these products altogether, but it's worth being deliberate about cleanup if you do use them. Wipe down any splashes immediately rather than letting them sit on tent fabric or flooring.

Clonex at Bunnings: Not a Knockoff

One genuine surprise in researching this article is that Bunnings actually stocks a real Clonex product: a 50ml bottle labelled as Yates Purple Clonex Rooting Hormone Gel. This isn't an imitation. It's the same Growth Technology Clonex formula, packaged and distributed under licence for Australian retail in a smaller bottle.

This is the one product on this list where the Bunnings version isn't a compromise. It's the genuine article in a smaller format. The only real consideration is value. A 50ml bottle from Bunnings will cost more per millilitre than buying the same Clonex Rooting Gel in a larger bottle from a dedicated hydroponic supplier, which makes sense if you only need a small amount for occasional propagation, and makes less sense if you're cloning regularly and would benefit from the lower cost per application of a bulk size.

Frequently Asked Questions

Can I use Seasol in a hydroponic system?
Yes, in small amounts as a root tonic and stress reliever. Seasol contains almost no NPK content, so it won't replace a proper base nutrient, but it's genuinely low risk for supporting root development and helping plants recover from transplant shock.

Is PowerFeed or Charlie Carp good enough for flowering crops?
Not on their own. Both carry real nitrogen and potassium but are too low in phosphorus for serious flowering and fruiting performance. A purpose-built flowering nutrient will outperform either at the stage where phosphorus demand rises.

Does Bunnings sell a real hydroponic-specific nutrient?
Yes. Manutec is an Australian-made range sold specifically for hydroponic systems, not a repurposed garden fertiliser. It works well for leafy greens and vegetables, though it doesn't disclose chelated micronutrients, which matters more for high-value flowering crops.

Is Superthrive safe to use in a hydroponic reservoir?
Multiple experienced growers report that leaving Superthrive in a reservoir continuously causes algae and bacterial blooms within two to three days. A single, one-off application during transplant shock carries less reported risk than ongoing reservoir dosing.

Can splashing organic fertiliser inside a grow tent cause mould?
Yes. Organic, unrefined products like Charlie Carp and Gogo Juice leave real organic residue if splashed on tent walls or floors during hand watering, and that residue combined with grow tent humidity is exactly what mould spores need to establish.

Is the Clonex sold at Bunnings the same as the hydroponic shop version?
Yes. Bunnings stocks a genuine 50ml Yates Purple Clonex Rooting Hormone Gel, made under licence using the same Growth Technology formula sold through hydroponic retailers, just in a smaller bottle.

None of the Bunnings products covered here were designed with hydroponic EC precision in mind, and that's the real, defensible reason a dedicated hydroponic nutrient outperforms them rather than any claim that garden centre products are inherently inferior. Seasol does almost nothing nutritionally and is low-risk because of it. PowerFeed and Charlie Carp carry real nitrogen and potassium but fall short on phosphorus for flowering crops. Gogo Juice introduces a live biological culture into a system not built to balance it. Yates Thrive has the best raw NPK numbers but no calcium or magnesium support and a real salt buildup risk in a recirculating system. Superthrive carries a genuine, well-documented contamination risk when left in a reservoir continuously. And Clonex at Bunnings is, refreshingly, exactly what it says it is.

If you do choose to experiment with any of these, dose in small increments and test EC after every addition rather than trusting the bottle's instructions, which were never written with a recirculating hydroponic reservoir in mind.