Top-Max by BioBizz — Organic Flowering Stimulator with Humic & Fulvic Acids
SG-S1979
100% organic flowering stimulator built on humic acids from Leonardite and fulvic acids. 1ml per litre in early flower rising to 4ml before the flush, for bigger, heavier, sweeter flower clusters.
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Pairs well with
Top-Max is BioBizz's 100% organic flowering stimulator, and it does its work through two very old ingredients. The humic acids come mainly from Leonardite, a deposit left by prehistoric trees and vegetation from the Carboniferous period around 300 million years ago. The fulvic acids come from exceptionally rich humate deposits deep in the earth, and their natural electrical charge attracts nutrients and minerals, freeing up calcium, iron and magnesium that were sitting locked in the substrate and stimulating the plant's metabolism. BioBizz lists three results: ingredients that can help increase the actual size and weight of the flower clusters, improved nutrient uptake, and sweeter, smoother-tasting crops. It runs the entire flowering period at 1–4ml per litre, starting low and climbing to 4ml as harvest approaches, before the flush. Available in 500ml, 1L and 5L.
Specifications
Grower's Tip
- Low and slow. The AU chart runs 1ml per litre in flowering week 1, 2ml in weeks 2–3, 3ml in weeks 4–5 and 4ml in weeks 6–7, then back to 1ml in week 8 and plain water in week 9. The build is the point. Do not open at 4ml.
- It is a stimulator, not a feed. Top-Max improves the uptake of what is already in the pot; it does not supply the NPK. Bio-Bloom is the flowering feed and Top-Max goes on top of it.
- Humic acid is dark and it stains. Measure over the sink or a tray, cap it straight away, and do not leave the syringe on the bench.
- Dose by ml, not EC. An organic humic and fulvic product barely registers on an EC meter, so the reading tells you nothing useful. 2ml per litre is 20ml in a 10-litre can.
- Shake it first. Humic concentrates settle. Shake, measure, then stir the can through before it goes near a pot.
- The minerals it frees up have to be there to free. On a fertilised substrate or buffered coco they are; on a bare, exhausted mix there is less for Top-Max to work with, which is one reason BioBizz says it works especially well with its own substrates.
- Week 9 is water only. The flush is part of the chart. Top-Max at 4ml in weeks 6–7 then 1ml in week 8 sets the plant up for it.
- Modest beats more. BioBizz says it across the range: it is always better to be modest than to add more. Stacking a mineral PK booster on top of Top-Max and Bio-Bloom is where organic grows go wrong.
How To Use It
Pairs Well With
The flowering feed Top-Max is designed to sit on. Run both from week 1 of flower, Bio-Bloom as the feed and Top-Max as the stimulator.
Bio-Grow by BioBizzStays in the feed through flower on the BioBizz chart. Its sugar beet base feeds the microbes that Top-Max's humic and fulvic acids work alongside.
Bio-Heaven by BioBizzAmino acid energy booster that peaks at 5ml per litre in flowering weeks 4–5, while Top-Max is climbing to its own peak.
Alg-A-Mic by BioBizzCold-pressed seaweed for stress recovery through flower. Low NPK, so it sits alongside Top-Max without overfeeding.
Great White MycorrhizaeInoculate at transplant and the fungal network is in place by the time Top-Max starts freeing up minerals for it to deliver.
Bloom Boosters RangeOrganic and mineral flowering boosters, carbs and ripeners, side by side.
Frequently Asked Questions
What is BioBizz Top-Max and what does it do?
Top-Max is a 100% organic flowering stimulator. BioBizz gives three reasons to use it: it contains ingredients that can help increase the actual size and weight of the flower clusters, it improves nutrient uptake, and plants grown with it produce sweeter, smooth-tasting crops. It works by freeing up calcium, iron and magnesium in the soil, which stimulates the plant's metabolism.
What is the Top-Max dose rate?
1–4ml per litre of water across the flowering period. BioBizz advises 1ml per litre in the first weeks of flowering, increasing to 4ml per litre as harvest approaches and before flushing. The Australian schedule spells it out: 1, 2, 2, 3, 3, 4, 4, 1ml per litre across flowering weeks 1–8, then plain water in week 9. The same numbers apply on coco / light mix and on fertilised substrate.
What are humic and fulvic acids, and why Leonardite?
Humic and fulvic acids are the organic acids left behind when plant matter breaks down over geological time. BioBizz's main humic source is Leonardite, a deposit formed from prehistoric trees and vegetation that flourished in the Carboniferous period around 300 million years ago. The fulvic acids come from rich humate deposits deep in the earth. BioBizz says their natural electrical charge attracts nutrients and minerals in the soil, and that together they boost the energy in old plant cells while stimulating new ones to form.
When do I start Top-Max?
In the first week of flowering, at 1ml per litre. There is no propagation or veg dose on the BioBizz schedule. It then runs every feeding week of flower until the flush.
Do I use Top-Max with Bio-Bloom or instead of it?
With it. Bio-Bloom is the flowering fertiliser; Top-Max is the stimulator that improves uptake of what Bio-Bloom and the substrate supply. BioBizz runs Bio-Grow, Bio-Bloom and Top-Max together through flower, with Bio-Heaven and Alg-A-Mic as the optional boosters.
Can I use Top-Max in coco or hydroponics?
Coco, yes: the AU coco / light mix chart includes it, with BioBizz's standard coco condition of adjusting pH and using an enzyme product. BioBizz also lists hydroponics as an application, but there is no hydro column on the Australian schedule, so in a recirculating system start at 1ml per litre and watch the reservoir.
Does Top-Max really change the taste?
BioBizz's claim is that improved nutrient flow through flower produces sweeter, smooth-tasting crops. It is a manufacturer claim about the process, not a guarantee about your harvest, and your drying and curing will have at least as much say in the result.
Is Top-Max organic?
BioBizz lists Top-Max with an Ecocert attestation and Control Union certification as an organic input under both the EU regulation and the US National Organic Program, plus Clean Green and EnvirOganic. Those are overseas input certifications rather than an Australian organic certification. It carries the BioBizz vegan icon on the AU schedule.
What is the NPK of Top-Max?
BioBizz does not publish an NPK analysis for Top-Max on its product page or 2026 data sheet. It is sold as a stimulator rather than a fertiliser, and its description is about humic and fulvic acids freeing up minerals, not supplying them. Dose by ml per litre, not by EC.
Which size should I buy?
At 1–4ml per litre over eight flowering weeks, the 500ml covers a small tent for a cycle with room to spare, the 1L makes 250–1,000 litres of solution, and the 5L is for a full room or a serious outdoor season.
Select Size
Give Your Flowers Something Ancient
Humic and fulvic acids from Leonardite. 1–4ml per litre, first flower to flush.
