Optic Foliar Watts - Foliar Feed for Light Efficiency
Best for: Growers who want their plants to make better use of the light they're already running, applied as a foliar spray alongside Optic Foliar Transport.
Our thoughts
Watts is a support product, not a standalone miracle spray - it's built to work best paired with Transport, which acts as the delivery vehicle that gets it into the leaf without residue. Used together they're a tidy little combo for pushing growth rate up a notch without messing with your root feed.
Optic Foliar Watts is a foliar supplement built around chelated iron, magnesium and sulfur (from potassium sulfate, monopotassium phosphate, magnesium sulfate and iron EDTA), aimed at supporting chlorophyll and chloroplast production so plants can make more efficient use of whatever light source they're grown under - HID, LED or natural sunlight. Its NPK is minimal (roughly 0-0.2-0.2), confirming this is a targeted micronutrient supplement rather than a feed.
Watts is designed to be used alongside Optic Foliar Transport, which acts as a carrier that helps Watts absorb straight into the leaf rather than sitting on the surface as residue. Sprayed together, the combination is formulated to be safe with lights on, avoiding the leaf-burn risk that comes with some foliar sprays applied under intense light.
How it compares
Watts occupies a fairly specific niche - light-efficiency foliar feeds - that most nutrient brands don't address directly.
- General base nutrient ranges like Canna or Advanced Nutrients don't offer a dedicated light-efficiency foliar product in the same way; this is a supplement layer on top, not a substitute.
- House & Garden's Multi-Vitamin range targets general plant vigour rather than chlorophyll/light-use efficiency specifically, so the two aren't direct swaps.
- Watts is designed as part of a three-product Optic Foliar stack (with Transport and REV), so its main "competition" is really other multi-product foliar systems rather than single bottles.
If chlorophyll efficiency and light utilisation is the specific thing you're trying to dial in, Watts is a more targeted choice than a general-purpose foliar vitamin spray.
Usage guidance
Watts is a concentrate and should always be used with Transport as the delivery agent.
Dosage
Optic Foliar's guidance is 7.5ml (around 1.5 teaspoons) each of Transport, REV and Watts per litre of spray solution.
Application frequency
Spray 2-3 times per week through the growth stage and up to around week 4 of flower.
Timing
Can be applied with lights on when mixed with Transport as directed - no need to wait for a dark period.
Technical specifications
- Product type: Foliar micronutrient feed for light-use efficiency
- NPK ratio: Approx. 0-0.2-0.2
- Key elements: Chelated iron, magnesium, sulfur
- Sourced from: Potassium sulfate, monopotassium phosphate, magnesium sulfate, iron EDTA
- Required carrier: Optic Foliar Transport
- Application window: Growth stage through to approx. week 4 of flower
- Recommended frequency: 2-3 sprays per week
- Brand: Optic Foliar
Who this is for
- Growers running HID or LED lighting who want to squeeze more efficiency out of their existing setup
- Anyone already using Optic Foliar Transport and REV who wants to complete the three-product stack
- Growers comfortable with a structured spray schedule (2-3 times weekly through veg and early-mid flower)
- Growers looking for a lights-on foliar option rather than one that demands a dark period
Best suited to growers who already have a base nutrient dialled in and are looking for an additional efficiency edge, not a replacement feed.
Our take
Watts does one specific job - supporting chlorophyll production so plants use light more efficiently - and it does it as part of a simple two- or three-product foliar combo rather than asking you to overhaul your feeding schedule. It's not a base nutrient, so don't buy it expecting one.
Simple, reliable feeding that delivers results when used as directed alongside Transport.
