Using Our LED Grow Chart Without Supplemental CO₂

Yes. Run the same light levels and the same CropSalt feed chart without CO₂, and skip the CO₂ column. Supplemental CO₂ is optional in our program.

Our light targets are moderate: 800 PPFD in flower week 1, peaking at 1,100 in weeks 5–6 under LED. That isn't an extreme-light schedule that needs enrichment to work, so you don't need a lower-light chart or a weaker feed.

What stays the same

• Feed: Veg 4.6 g Veg A + 3.1 g Veg B per gallon, Bloom 5.1 g Bloom A + 2.6 g Bloom B from flower day 22 for photoperiods, then Cake to finish. Same chart with or without CO₂. Don't cut strength because you're at ambient CO₂.
• Light: the chart PPFD for each week, measured at the canopy, center and edges. Targets and the DLI math are in PPFD and DLI.
• VPD and leaf temperature: the same stage targets. Check them with measured leaf temperature in our VPD calculator.
• Watering: matched to how fast the pots dry, not to whether CO₂ is on.

Keep fresh air coming in

Without enrichment, the plants use the CO₂ that's already in the air. In a ventilated room, fresh-air exchange keeps supplying it, so keep that air exchange working. A sealed room with no fresh air and no CO₂ added is a different situation from a normal room running without enrichment.

If you add CO₂ later

• Chart levels (LED): 450 ppm in veg week 1 up to 700 by veg week 4; 1,000 ppm in flower week 1, peaking at 1,300 in weeks 5–6 and tapering to 800 by week 9.
• Ramp it. We start low and increase gradually. Don't jump a veg room straight to flower levels.
• Same feed. Adding CO₂ doesn't call for a new A:B ratio or a stronger mix.
• Test it cleanly. If you want to know what CO₂ did, change only CO₂ on matched plants. Add more light, new pots and CO₂ at once and you can't tell which one made the difference.

More light and CO₂ aren't automatically the answer either. Check canopy PPFD, leaf temperature and VPD together before you push a room harder.

If plants look off

Don't blame the missing CO₂ first. Check feed and runoff pH and EC, delivery and the environment, the same way you would in any room. Our troubleshooting checklist walks through it.