Aptus - Topbooster

Topbooster is Aptus's bloom and ripening stimulator. The first thing worth noticing is in the directions rather than the marketing: you use 20 ml per 100 litres. That is a dilution of 1 in 5,000, and the figure tells you immediately what kind of product this is.

What a 1:5,000 dose means

Set that ratio against the rest of this shelf. A PK ripener usually goes in at 1 ml per litre, so 1:1,000. A bloom stimulator often sits at 2 ml per litre, 1:500. Topbooster sits a factor of five to ten below both.

That difference is not thrift but a difference in category. A product you dose at 1:500 supplies building materials: phosphorus, potassium, nitrogen, things a plant physically turns into mass. At 1:5,000 that is not possible. At that dilution there is simply too little material in your reservoir to feed a plant with.

What happens instead is signalling. The active substances in Topbooster act on processes the plant carries out itself, and you need very little of those because they are switched on rather than built up. Aptus put it the same way: use Topbooster as a supplement beside your NPK feed, not instead of it.

In practice that is convenient. Your EC barely moves, so you do not have to pull your base feed back for it, and a small bottle lasts. At 20 ml per 100 litres, 100 ml makes up 500 litres of feed water.

What is in it

Aptus list the active components: amino acids, polysaccharides, trace elements in the form of boron, iron and molybdenum, natural bloom-promoting plant hormones of which they name auxins, and vitamin complexes.

That is a different kind of list from an analysis. There is no NPK on it and Aptus publish none, because that belongs to your base feed. What is there is a set of substances each acting on part of the flowering process: polysaccharides assist nutrient uptake, trace elements such as boron and molybdenum are precisely the ones involved in flower set, and vitamins and hormones sit in the signalling.

The effect Aptus describe is the formation of large flowers with plenty of fibre and sugars, with quality of appearance and taste as the second point. Topbooster is a fully organic product.

Start early and keep going

Aptus explicitly advise early and prolonged use, which is less obvious for a bloom product than it sounds. Most bottles on this shelf are ripeners that only go in for the final weeks. Topbooster runs from the second week of flowering through to the last.

The reason they give is that the product carries a complete mix acting on the whole flowering process, from first flower set to ripening. Bring it in late and you miss half of what it was built for.

The dose may climb. Aptus name 2 ml per 10 litres as the starting point and say you can work up to 4 ml per 10 litres over the cycle for a stronger effect.

Organic, and what that does to your lines

A warning belongs here that Aptus give themselves and that you will not read anywhere else. A fully organic product in a fine drip system raises the risk of blockages.

That is not a reason to avoid it, but it is a reason to add something. Aptus specify that when using Topbooster in drip irrigation you should always give System-Clean alongside, which clears organic material out of your lines before it becomes a film.

If you water by hand this does not arise. If you run drippers or misters with fine openings, this is the instruction you will not find again a few pages further on.

Add Topbooster to your reservoir last, once your base feed is properly mixed.

Available sizes

Technical Specifications:

• Type: bloom and ripening stimulator, 100% organic
• Manufacturer: Aptus
• Dose: 20 ml per 100 litres of water, meaning 1:5,000
• May be built up to: 4 ml per 10 litres over the cycle
• Period: from the second week of flowering through to the last
• Stated components: amino acids, polysaccharides, boron, iron and molybdenum, natural plant hormones and vitamin complexes
• Analysis: none, this is a supplement beside your NPK feed
• Order: add last, after your base feed
• With drip systems: always use together with System-Clean
• Does not replace: your base feed

Frequently asked questions

Why is the dose so low?
Because it is not a feed. At 1:5,000 you are steering processes rather than supplying building material; the building material comes from your base feed.

When do I start?
In the second week of flowering, and you continue through the last week. Aptus specifically advise early and prolonged use.

Can I run it through a drip system?
Yes, but give System-Clean alongside. An organic product raises the blockage risk in fine systems, and Aptus specify this themselves.

Do I need to adjust my EC?
At this dilution your EC barely moves. Measure after mixing as you always would.

What is the NPK?
There isn't one. Topbooster is a supplement beside an NPK fertiliser and Aptus publish no analysis for it.