Growth Technology

Why Growth Technology

Growth Technology have been making nutrients since the 1980s and manufacture in Perth, which matters more than it sounds. The formulas are built around Australian water profiles rather than adapted from a European or American base, and if you have ever fought an imported nutrient line against hard Melbourne tap water you will know why that is worth something.

The range splits into two halves that suit completely different growers, and it is worth knowing which one you are shopping.

The hydroponic side

For hydro, coco and soil, GT Optimum Grow & Bloom covers the full cycle as a 2-part A+B, and GT Iconic does the same job in one bottle per stage if you would rather not measure two. For coco specifically, GT Coco A & B carries the calcium, magnesium and iron already built in, so you are not buying a separate Cal-Mag every time.

On the additive side, GT Silica goes in early for stem and cell wall strength. Put it in the water first, before anything else, since potassium silicate is strongly alkaline and will react with your other concentrates if you add it last. Into flower, GT Super PK is the high-PK push, GT Rootzone supports root development from transplant onward, and GT Fulvic improves how much of what you feed actually gets taken up. GT Foliar RTU is a ready-to-use leaf spray for correcting a visible deficiency faster than the root zone can. Keep pH in range with GT pH Up & Down.

The Focus range, for everything that is not a hydro crop

Thirteen of the products here are GT Focus, and they are a different proposition entirely. Each one is a single-bottle feed built for one plant type, and the reason to buy a specialist feed is that the ratio is different, not that it is stronger.

Native Focus is the clearest example. Australian natives evolved in phosphorus-poor soil and a standard fertiliser will kill Grevilleas, Banksias and Proteas over a season or two. Low phosphorus is the entire point of it. Succulent Focus runs deliberately lean, because succulents fail from too much feed far more often than too little. Chilli Focus is built around calcium keeping up with fruit load, which is what stops splitting and blossom end rot.

Orchids get three, because they need different things at different times: Orchid Focus urea-free for general feeding, Orchid Grow for the months between flowering, and Orchid Bloom for once a spike appears. The rest cover foliage, flowers, fruit, vegetables, herbs, roses, and an all-purpose Complete for anything that is not a specialty crop.

Before you buy another bottle

If you are here because something is yellowing and you are trying to work out which additive fixes it, it is worth checking the diagnosis first. Interveinal yellowing is magnesium, iron or a pH lockout depending on which leaves are affected, and only one of those is solved by feeding. PlantMDx will narrow it down in about a minute. Free, no signup, and it will tell you if the answer is a pH correction rather than another product.

Our nutrient deficiency chart covers the same ground in more detail, and what EC should I run has the target ranges by stage if you are dialling in a feed rather than fixing a problem.

Also in this collection: pH Buffer 4 and 7 calibration sachets and 99.9% isopropyl alcohol for cleaning probes and equipment.

Frequently Asked Questions

What is the difference between GT Optimum and GT Iconic?
Optimum is a 2-part A+B, Iconic is a single bottle per stage. Same manufacturer, same water profile behind them. Iconic is simpler to mix, Optimum gives you more control over the ratio.

Do I still need Cal-Mag if I am running GT Coco?
No. GT Coco has elevated calcium, magnesium and iron built in specifically because coco binds calcium more aggressively than other media. That is the point of the coco-specific formula.

Why does GT Silica have to go in the water first?
Potassium silicate is strongly alkaline. Added to an already mixed reservoir it can react with your other concentrates and drop things out of solution. Water first, Silica second, everything else after.

Can I use a Focus formula on a different plant type?
It will not hurt the plant, but you lose the reason for buying it. The difference is the NPK ratio and trace element balance. The one exception is Native Focus, which you should not substitute for, and should not substitute with, since phosphorus-sensitive natives genuinely die from standard fertilisers.

Can I mix Growth Technology with another brand?
Additives like Silica and Fulvic mix fine with most base lines. Keep the base nutrient itself consistent rather than running two different base systems together.