Photosynthesis Plus 3.8L

Photosynthesis Plus 3.8L — Microbial Inoculant for Root Zone & Foliar Boosting

Best for: Growers wanting to unlock better nutrient uptake, photosynthetic efficiency, and plant stress tolerance without adding complexity to their feed schedule

Photosynthesis Plus is a liquid microbial inoculant containing a carefully fermented consortium of beneficial bacteria strains, including photosynthetic bacteria (Rhodopseudomonas palustris) and Bacillus species. It's designed to improve nutrient uptake, boost chlorophyll production, strengthen plant immunity, and help plants handle stress — all without needing to overhaul your nutrient schedule. The 3.8L format is the bulk size, built for growers running multiple systems or larger spaces where microbial boosting makes real economic sense.

How it compares

Photosynthesis Plus sits in the microbial inoculant category, but it's distinct from phosphorus-focused boosters and fungal products.

• vs Mammoth P: Mammoth P targets phosphorus mobilisation specifically. Photosynthesis Plus works on overall photosynthetic efficiency and broad nutrient cycling — different jobs, both useful
• vs Fungi-based products (MycoBoost, Unleash): Those rely on mycorrhizal fungi and Trichoderma. Photosynthesis Plus is bacteria-focused, working directly in the root zone and as a foliar feed
• vs SLF-100: Commonly paired together. Many growers run both for synergistic effect
• Works across all growing mediums — soil, coco, hydro, NFT, drip systems
• Active, living culture that continues working in the bottle (which is why it smells like a composting yard — that's bacterial activity, not a fault)

Usage guidance

Photosynthesis Plus works two ways: root zone feeding and foliar spray. It's flexible enough to fit most growing schedules.

Root zone / Irrigation applications
Add 2 fl oz per 5 gallons of water for initial applications, then 1 fl oz per 5 gallons weekly or at water changes. Works in hand-watered systems, drip lines, and hydroponic reservoirs equally well. Some growers find they can reduce nutrient strength once they start using it regularly — test and dial in what works for your setup.

Foliar spray applications
Mix 1–2 fl oz per gallon of water and spray every 2–4 weeks, or at your regular watering interval. Use roughly 1–2 gallons per 1,000 sq ft depending on coverage. Light spray is fine — you're inoculating the leaf surface and supporting uptake, not drenching.

Storage and longevity
Shelf-stable for two years unopened. Once opened, keep it sealed tightly and it'll last around a year. It's a living product, so the culture is active in the bottle — that's why it needs proper closure and why it smells earthy and funky. That's working, not broken.

Integration with other products
Photosynthesis Plus works well alongside other microbial boosters. Many growers use it with Mammoth P or SLF-100 for layered microbial coverage. No antagonism reported — they complement each other.

Technical specifications

• Volume: 3.8L (approximately 1 US gallon equivalent)
• Active culture: Two select photosynthetic bacterial strains + four Bacillus strains, fermented together over six days
• Key strain: Rhodopseudomonas palustris (photosynthetic bacteria)
• Shelf life: 2 years unopened; 2.5 years if stored correctly
• Once opened: approximately 1 year if kept sealed and in original container
• Dosage (root zone): 2 fl oz per 5 gallons initial; 1 fl oz per 5 gallons weekly thereafter
• Dosage (foliar): 1–2 fl oz per gallon of water; apply every 2–4 weeks
• Medium compatibility: Soil, coco, hydroponic (DWC, NFT, drip systems)

Who this is for

• Growers running hydroponic or coco systems where light efficiency and nutrient cycling matter
• Anyone looking to improve plant stress tolerance without pharmaceutical interventions
• Growers already using Mammoth P or SLF-100 who want to layer in photosynthetic bacteria
• Larger operations or multi-system growers where the 3.8L bulk size makes economic sense
• Growers willing to let the biology do some of the heavy lifting rather than pushing nutrients harder

Our take

This is a proper microbial product that does what it claims. The photosynthetic bacteria angle is legitimate — you're not just improving root colonisation, you're genuinely improving how plants capture light energy. That translates to better growth, better stress handling, and in many cases, lower nutrient requirements.

The 3.8L format is worth it if you're running multiple systems or treating a larger space regularly. You'll use it. Growers who've committed to it report noticeable results within 2–3 weeks, and it integrates cleanly into most feeding schedules without drama. Worth picking up while clearance stock lasts.