{"product_id":"the-source-gro-a-b","title":"The Source Gro A\u0026B – Vegetative Stage Nutrients","description":"\u003ch2\u003eA Two-Part Grow Feed With Amino, Fulvic and Humic Acids\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eThe Source Gro A\u0026amp;B\u003c\/strong\u003e is the two-part base nutrient for the \u003cstrong\u003egrowth and vegetative stage\u003c\/strong\u003e in The Source range, sold as a matched Part A and Part B set. \u003cstrong\u003eGro A\u003c\/strong\u003e has an NPK of \u003cstrong\u003e5-0-2\u003c\/strong\u003e and \u003cstrong\u003eGro B\u003c\/strong\u003e an NPK of \u003cstrong\u003e1.2-2-4\u003c\/strong\u003e, with Part B carrying the trace elements zinc, boron, copper, cobalt, molybdenum and EDTA-chelated manganese. Both parts add \u003cstrong\u003eamino acids, fulvic acids, natural humic acids, vitamins, sugars\u003c\/strong\u003e and natural stress-relieving agents, and Gro A includes natural plant-extract growth hormones, with no artificial plant growth regulators. It was designed for \u003cstrong\u003eAutoPot Watering Systems\u003c\/strong\u003e but suits every hydroponic feeding method, in soil, coco or hydro, on hard or soft water, and gives relentless, even growth that sets plants up for flowering.\u003c\/p\u003e\n\u003ch3\u003eKey Benefits\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBalanced two-part feed\u003c\/strong\u003e — Gro A \u003cstrong\u003e5-0-2\u003c\/strong\u003e and Gro B \u003cstrong\u003e1.2-2-4\u003c\/strong\u003e, mixed in equal amounts.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOrganic acids built in\u003c\/strong\u003e — amino, fulvic and humic acids, vitamins and sugars support root development and nutrient uptake.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFull trace-element package\u003c\/strong\u003e — zinc, boron, copper, cobalt, molybdenum and chelated manganese in Part B.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStress-relieving agents\u003c\/strong\u003e — help plants hold steady through heat and transplanting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEconomical\u003c\/strong\u003e — full strength is just \u003cstrong\u003e1 ml of each part per litre\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAny medium, any water\u003c\/strong\u003e — soil, coco and hydro; hard or soft water.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSlow, Uneven Vegetative Growth\u003c\/h3\u003e\n\u003cp\u003eToo weak a feed in veg gives pale, slow plants; too strong and young roots scorch. Gro is dosed by EC: equal parts of A and B into the water until you hit a gentle EC for young plants, raised as they grow, so vegetative growth stays fast and uniform and plants go into flowering with strong structure and healthy roots. The vegetative stage can run as long as you need, though the maker advises not switching to flowering before week two.\u003c\/p\u003e\n\u003ch3\u003eHow to Use\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMixing:\u003c\/strong\u003e add \u003cstrong\u003eequal amounts of Part A and Part B\u003c\/strong\u003e to the water, stirring between parts, until you reach your target EC. Measure your plain water first; tap water usually reads between \u003cstrong\u003e0.1 and 0.8 EC\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEC:\u003c\/strong\u003e keep young plants low at about \u003cstrong\u003e1.0–1.4 EC\u003c\/strong\u003e, rising to \u003cstrong\u003e1.7–2.4 EC\u003c\/strong\u003e as they grow, per The Source's guidance.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStimulators after:\u003c\/strong\u003e add Origin, Delta, Elements or Alluvium once A and B are in; EC will rise by about 0.4–0.7, which is expected.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSoil and compost (AutoPot and greenhouse charts):\u003c\/strong\u003e \u003cstrong\u003e0.25 ml of each part per litre\u003c\/strong\u003e for weeks one and two, 0.5 ml for weeks three and four, then \u003cstrong\u003e1 ml\u003c\/strong\u003e from week five (label range 0.25–1 ml).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCoco and hydro, and any medium on hand watering, drip, NFT or flood and drain:\u003c\/strong\u003e \u003cstrong\u003e0.5 ml of each part per litre\u003c\/strong\u003e for weeks one and two, then \u003cstrong\u003e1 ml\u003c\/strong\u003e from week three (label range 0.5–1 ml for coco and hydro).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMoving to flowering:\u003c\/strong\u003e switch to \u003cstrong\u003eThe Source Flo A\u0026amp;B\u003c\/strong\u003e when the growth stage is complete.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003epH:\u003c\/strong\u003e set the reservoir to about \u003cstrong\u003epH 5.8\u003c\/strong\u003e for soil and compost and about \u003cstrong\u003epH 5.6\u003c\/strong\u003e for coco or rockwool, as The Source recommends.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cdiv class=\"hcs-specs\"\u003e\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eType:\u003c\/strong\u003e Two-part base nutrient, growth and vegetative stage\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGro A NPK:\u003c\/strong\u003e 5-0-2\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGro B NPK:\u003c\/strong\u003e 1.2-2-4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAlso contains:\u003c\/strong\u003e Amino acids, fulvic acids, natural humic acids, vitamins, sugars and natural stress-relieving agents; Part B adds zinc, boron, copper, cobalt, molybdenum and EDTA-chelated manganese; Part A adds natural plant-extract growth hormones\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePlant growth regulators:\u003c\/strong\u003e No artificial PGRs\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDose rate:\u003c\/strong\u003e Soil 0.25–1 ml of each part per litre; coco and hydro 0.5–1 ml of each part per litre\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGrowing media:\u003c\/strong\u003e Soil, coco and hydroponics\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWater:\u003c\/strong\u003e Suitable for hard and soft water\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSupplied as:\u003c\/strong\u003e Matched set of Part A and Part B\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMade in:\u003c\/strong\u003e United Kingdom\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hcs-dosing\" style=\"margin:32px 0 0;border:1px solid #e6e6e6;border-radius:12px;overflow:hidden;font-family:Montserrat,-apple-system,'Segoe UI',sans-serif;\"\u003e\n\u003cdiv style=\"background:#101010;padding:16px 20px;border-bottom:3px solid #efc04c;\"\u003e\n\u003cdiv style=\"color:#ffffff;font-size:17px;font-weight:600;letter-spacing:.06em;text-transform:uppercase;\"\u003eFeed Chart\u003c\/div\u003e\n\u003cdiv style=\"margin-top:6px;color:#b8b8b8;font-size:12px;line-height:1.5;\"\u003eGro A\u0026amp;B · doses are for EACH of Part A and Part B · growth stage\u003c\/div\u003e\n\u003c\/div\u003e\n\u003ctable style=\"width:100%;border-collapse:collapse;font-size:14px;color:#2b2b2b;background:#fff;\"\u003e\n\u003ctr style=\"background:#f4f4f4;\"\u003e\n\u003cth style=\"text-align:left;padding:10px 20px;font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:#6b6b6b;font-weight:600;\"\u003eStage\u003c\/th\u003e\n\u003cth style=\"text-align:right;padding:10px 14px;font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:#6b6b6b;font-weight:600;white-space:nowrap;\"\u003ePer 1 L\u003c\/th\u003e\n\u003cth style=\"text-align:right;padding:10px 20px;font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:#6b6b6b;font-weight:600;white-space:nowrap;\"\u003ePer 10 L\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:12px 20px;border-top:1px solid #ededed;\"\u003eAutoPot soil and greenhouse crops, weeks 1–2\u003c\/td\u003e\n\u003ctd style=\"padding:12px 14px;border-top:1px solid #ededed;text-align:right;white-space:nowrap;font-weight:600;\"\u003e0.25 ml\u003c\/td\u003e\n\u003ctd style=\"padding:12px 20px;border-top:1px solid #ededed;text-align:right;white-space:nowrap;color:#6b6b6b;\"\u003e2.5 ml\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fcfaf4;\"\u003e\n\u003ctd style=\"padding:12px 20px;border-top:1px solid #ededed;\"\u003eAutoPot soil and greenhouse crops, weeks 3–4\u003c\/td\u003e\n\u003ctd style=\"padding:12px 14px;border-top:1px solid #ededed;text-align:right;white-space:nowrap;font-weight:600;\"\u003e0.5 ml\u003c\/td\u003e\n\u003ctd style=\"padding:12px 20px;border-top:1px solid #ededed;text-align:right;white-space:nowrap;color:#6b6b6b;\"\u003e5 ml\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:12px 20px;border-top:1px solid #ededed;\"\u003eAutoPot soil and greenhouse crops, week 5 on\u003c\/td\u003e\n\u003ctd style=\"padding:12px 14px;border-top:1px solid #ededed;text-align:right;white-space:nowrap;font-weight:600;\"\u003e1 ml\u003c\/td\u003e\n\u003ctd style=\"padding:12px 20px;border-top:1px solid #ededed;text-align:right;white-space:nowrap;color:#6b6b6b;\"\u003e10 ml\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fcfaf4;\"\u003e\n\u003ctd style=\"padding:12px 20px;border-top:1px solid #ededed;\"\u003eAutoPot coco and hydro, and other watering methods, weeks 1–2\u003c\/td\u003e\n\u003ctd style=\"padding:12px 14px;border-top:1px solid #ededed;text-align:right;white-space:nowrap;font-weight:600;\"\u003e0.5 ml\u003c\/td\u003e\n\u003ctd style=\"padding:12px 20px;border-top:1px solid #ededed;text-align:right;white-space:nowrap;color:#6b6b6b;\"\u003e5 ml\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:12px 20px;border-top:1px solid #ededed;\"\u003eAutoPot coco and hydro, and other watering methods, week 3 on\u003c\/td\u003e\n\u003ctd style=\"padding:12px 14px;border-top:1px solid #ededed;text-align:right;white-space:nowrap;font-weight:600;\"\u003e1 ml\u003c\/td\u003e\n\u003ctd style=\"padding:12px 20px;border-top:1px solid #ededed;text-align:right;white-space:nowrap;color:#6b6b6b;\"\u003e10 ml\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003cdiv style=\"background:#101010;padding:12px 20px;font-size:12px;color:#b8b8b8;line-height:1.6;\"\u003e\n\u003cspan style=\"color:#efc04c;font-weight:600;\"\u003eNote\u003c\/span\u003e — The Source's labels and feed charts (AutoPot, greenhouse and other watering methods); always add equal amounts of A and B. Set EC first, then add any stimulators, then adjust pH.\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cdiv class=\"hcs-faq\"\u003e\n\u003cdetails style=\"border:1px solid #e6e6e6;border-radius:8px;padding:12px 16px;margin:0 0 8px;\"\u003e\u003csummary style=\"cursor:pointer;font-weight:600;\"\u003eDo I add the same amount of A and B?\u003c\/summary\u003e\u003cp style=\"margin:10px 0 0;\"\u003eYes. The Source's rule is always equal amounts of Part A and Part B into the water, adding both until you reach your target EC.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails style=\"border:1px solid #e6e6e6;border-radius:8px;padding:12px 16px;margin:0 0 8px;\"\u003e\u003csummary style=\"cursor:pointer;font-weight:600;\"\u003eHow long do I feed Gro before switching to Flo?\u003c\/summary\u003e\u003cp style=\"margin:10px 0 0;\"\u003eThe maker's growth chart runs six weeks and can be extended as long as you need; ideally do not stop before week two. Then change to Flo A and B for flowering.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails style=\"border:1px solid #e6e6e6;border-radius:8px;padding:12px 16px;margin:0 0 8px;\"\u003e\u003csummary style=\"cursor:pointer;font-weight:600;\"\u003eCan I use Gro without the rest of The Source range?\u003c\/summary\u003e\u003cp style=\"margin:10px 0 0;\"\u003eGro A and B are the complete base feed for the growth stage. The maker designs Origin, Delta and Elements to run alongside them and recommends its own range rather than other brands' additives.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails style=\"border:1px solid #e6e6e6;border-radius:8px;padding:12px 16px;margin:0 0 8px;\"\u003e\u003csummary style=\"cursor:pointer;font-weight:600;\"\u003eIs it suitable for hard water?\u003c\/summary\u003e\u003cp style=\"margin:10px 0 0;\"\u003eYes. The whole range is formulated for hard and soft water.\u003c\/p\u003e\u003c\/details\u003e\n\u003c\/div\u003e\n\u003ch3\u003eWorks Well With\u003c\/h3\u003e\n\u003cdiv class=\"hcs-related\" style=\"display:flex;flex-wrap:wrap;gap:10px;margin:12px 0 0;\"\u003e\n\u003ca href=\"\/products\/bluelab-nutrient-truncheon\" style=\"flex:1 1 240px;display:flex;align-items:center;gap:12px;padding:10px 12px;border:1px solid #e6e6e6;border-radius:8px;text-decoration:none;color:inherit;background:#fff;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0748\/7127\/5786\/files\/Bluelab-nutrient-truncheon-card.jpg?v=1746904762\u0026amp;width=160\" alt=\"Bluelab Nutrient Truncheon\" width=\"64\" height=\"64\" loading=\"lazy\" style=\"width:64px;height:64px;object-fit:contain;flex:none;\"\u003e\u003cspan style=\"font-size:14px;line-height:1.4;\"\u003e\u003cstrong style=\"display:block;\"\u003eBluelab Nutrient Truncheon\u003c\/strong\u003e\u003cspan style=\"color:#008d37;\"\u003eDoses A and B to your target EC\u003c\/span\u003e\u003c\/span\u003e\u003c\/a\u003e\n\u003ca href=\"\/products\/bluelab-ph-pen\" style=\"flex:1 1 240px;display:flex;align-items:center;gap:12px;padding:10px 12px;border:1px solid #e6e6e6;border-radius:8px;text-decoration:none;color:inherit;background:#fff;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0748\/7127\/5786\/files\/bluelab-PH-pen-2-medium_landscape.jpg?v=1746904767\u0026amp;width=160\" alt=\"Bluelab pH Pen\" width=\"64\" height=\"64\" loading=\"lazy\" style=\"width:64px;height:64px;object-fit:contain;flex:none;\"\u003e\u003cspan style=\"font-size:14px;line-height:1.4;\"\u003e\u003cstrong style=\"display:block;\"\u003eBluelab pH Pen\u003c\/strong\u003e\u003cspan style=\"color:#008d37;\"\u003eChecks pH once the feed is mixed\u003c\/span\u003e\u003c\/span\u003e\u003c\/a\u003e\n\u003ca href=\"\/products\/autopot-system\" style=\"flex:1 1 240px;display:flex;align-items:center;gap:12px;padding:10px 12px;border:1px solid #e6e6e6;border-radius:8px;text-decoration:none;color:inherit;background:#fff;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0748\/7127\/5786\/files\/autopot-system.jpg?v=1787260281\u0026amp;width=160\" alt=\"AutoPot System\" width=\"64\" height=\"64\" loading=\"lazy\" style=\"width:64px;height:64px;object-fit:contain;flex:none;\"\u003e\u003cspan style=\"font-size:14px;line-height:1.4;\"\u003e\u003cstrong style=\"display:block;\"\u003eAutoPot System\u003c\/strong\u003e\u003cspan style=\"color:#008d37;\"\u003eThe gravity-fed pots Gro was designed for\u003c\/span\u003e\u003c\/span\u003e\u003c\/a\u003e\n\u003c\/div\u003e","brand":"The Source","offers":[{"title":"5L (A\u0026B)","offer_id":53931040342282,"sku":"NUT-THES-005-01","price":59.9,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0748\/7127\/5786\/files\/the-source-gro-a-b-5l-a-b-1.jpg?v=1792294405","url":"https:\/\/hydrocropshop.co.uk\/products\/the-source-gro-a-b","provider":"Hydro Crop Shop","version":"1.0","type":"link"}