Cyco Nutrients - Platinum Series - Swell - Late-Flower PK Booster for Bigger Finishing Weight
Best for: growers in the final weeks of flower who want to push size and density before harvest.
Our thoughts
Swell is Cyco's answer to the classic late-flower PK booster, and it does the job the category is known for: pushing plants harder in the closing weeks when they're bulking up. Pair it with an early-flower product like Potash Plus and you've got the flowering stage properly covered end to end.
Swell is formulated with nutrients that help push plants to their limits during the final weeks of flower, delivering generous doses of phosphorus, potassium and magnesium. These are the core building blocks most closely associated with late-flower bulking, and Swell is designed to supply them at levels a standard base nutrient typically doesn't.
It's used as a top-up to your existing base feed rather than a replacement for it, dosed specifically in the later stages of flower when plants are putting on the bulk of their final weight.
How it compares
Late-flower PK boosters are one of the most established additive categories, and Swell sits alongside some well-known names.
- Canna PK 13/14 is probably the most recognised PK booster on the market and the standard many growers measure others against.
- Advanced Nutrients Big Bud covers similar late-flower bulking territory with a comparable phosphorus-and-potassium focus.
- Aptus Super PK is another concentrated PK product used at the same growth stage.
Swell's phosphorus, potassium and magnesium combination is a slightly broader spread than a pure PK product, which is worth knowing if you're already supplementing magnesium separately.
Usage guidance
Use it in the back half of flower, not throughout the whole cycle.
Timing
Introduce Swell once your plants are past the stretch phase and into bulking, typically the final weeks before harvest.
Dosing
Follow the dose rate on the bottle or Cyco's Platinum Series feed chart, adding it on top of your regular base feed.
Watch your EC
Because it's a concentrated booster on top of a base feed, keep an eye on total EC/PPM so you don't overshoot what your plants can use.
Technical specifications
- Key nutrients: Phosphorus, potassium, magnesium
- Brand: Cyco Platinum Series
- Product type: Late-flower PK booster
- Recommended window: Final weeks of flowering
- Format: Liquid concentrate
- Suitable systems: Hydroponic, coco and soil setups
- Pack sizes: Available in multiple bottle sizes
Who this is for
- Growers wanting to push size and density in the final stretch of flower
- Anyone already running a Cyco Platinum Series base feed and additive programme
- Growers who want a PK booster with added magnesium in one bottle
Our take
Swell does exactly what a late-flower PK booster is supposed to do, and the added magnesium is a sensible extra rather than a gimmick. It's a solid pairing for anyone running Potash Plus earlier in the cycle and wanting to see the flowering stage through properly.
Does exactly what it should, day in, day out. One we sell a lot of for growers finishing off a flower cycle.
