{"product_id":"grenade-black-natural-pk-bloom-hardener","title":"Natural PK Bloom Hardener – Grenade Black","description":"\u003ch2\u003eThe bottle costs £40. The feed costs pennies a litre.\u003c\/h2\u003e\n\u003cp\u003eMost people judge a bloom booster by the price on the bottle. That's a bit like judging a car by the price of its key. Grenade Black is so concentrated that even at the full recommended dose of \u003cstrong\u003e0.4ml per litre\u003c\/strong\u003e, a single 100ml bottle treats \u003cstrong\u003e250 litres\u003c\/strong\u003e of feed – about 16p per litre of water. Many PK boosters ask for 1–2ml per litre. The grenade isn't the expensive bit. It's a reminder that small things can carry a lot of force.\u003c\/p\u003e\n\u003ch3\u003eWhat it is\u003c\/h3\u003e\n\u003cp\u003eGrenade Black is an advanced hybrid organo-mineral PK+ flowering additive, blended as a natural alternative to synthetic chemical hardeners. It doesn't force a plant into shape – it gives it what it needs to reach its own genetic potential. Phosphorus and potassium drive flower and fruit set, while amino acids, minerals and biological cofactors support plant energy levels (ATP) and the production of secondary metabolites: the compounds behind aroma, flavour and colour.\u003c\/p\u003e\n\u003ch3\u003eWhy growers rate it\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDenser, heavier, healthier flowers and fruit\u003c\/strong\u003e through the critical mid-to-late bloom window\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e100% natural PK+ hardener\u003c\/strong\u003e – no synthetic growth regulators\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUltra-concentrated\u003c\/strong\u003e – 100ml treats 250–500L, 1L treats 2,500–5,000L\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePlays well with others\u003c\/strong\u003e – compatible with all nutrient regimes in hydro, coco and soil\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eNot just for the grow tent\u003c\/h3\u003e\n\u003cp\u003eAnything that flowers or fruits can use the help: tomatoes, chillies and sweet peppers, strawberries, aubergines, cucumbers and flowering houseplants. Whether you're growing in a greenhouse, a conservatory or on a sunny windowsill, this is the late-season feed that turns flowers into a crop.\u003c\/p\u003e\n\u003ch3\u003eHow to use\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDose:\u003c\/strong\u003e 0.4ml per litre for full effect (0.2ml per litre is the minimum). Don't go above 0.4ml – more isn't better past that point.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWhen:\u003c\/strong\u003e weeks 3 to 7 of the flowering cycle. Start in week 3 and use it at every feed through to the end of week 7, then stop.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eContinuous croppers\u003c\/strong\u003e (tomatoes, chillies, peppers, strawberries): start once the first fruits have set and use it at every feed through the main fruiting period.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOrder:\u003c\/strong\u003e add Grenade Black to your water first, then top up with base nutrients and other additives to reach your target EC.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStorage:\u003c\/strong\u003e keep in a cool, dry place.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ctable\u003e\n\u003ctr\u003e\n\u003cth\u003eSize\u003c\/th\u003e\n\u003cth\u003eAt 0.4ml\/L\u003c\/th\u003e\n\u003cth\u003eAt 0.2ml\/L\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e100ml\u003c\/td\u003e\n\u003ctd\u003e250 litres\u003c\/td\u003e\n\u003ctd\u003e500 litres\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e250ml\u003c\/td\u003e\n\u003ctd\u003e625 litres\u003c\/td\u003e\n\u003ctd\u003e1,250 litres\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e1 Litre\u003c\/td\u003e\n\u003ctd\u003e2,500 litres\u003c\/td\u003e\n\u003ctd\u003e5,000 litres\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e5 Litre\u003c\/td\u003e\n\u003ctd\u003e12,500 litres\u003c\/td\u003e\n\u003ctd\u003e25,000 litres (made to order)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003ch3\u003e🌱 Rose's Pro-Tip\u003c\/h3\u003e\n\u003cp\u003eDon't ration it – there's no prize for a half-full bottle at the end of the season. At full dose a 10 litre watering can needs just 4ml, so use the dropper or a small syringe rather than eyeballing it. And let Grenade Black be your only PK booster while you're using it – stacking two PK products at once is how plants get overloaded.\u003c\/p\u003e\n\u003ch3\u003eBetter together: Grenade White\u003c\/h3\u003e\n\u003cp\u003eGrenade White builds the frame from seed onwards with stabilised silicic acid; Grenade Black fills it out in bloom.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFree UK delivery on every Grenade order – no minimum spend.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003eGrenade Nutrients, stocked by Black Flag Horticulture, Coventry. The 5 litre size is made to order, so please allow a little extra time for dispatch.\u003c\/em\u003e\u003c\/p\u003e","brand":"Grenade Nutrients","offers":[{"title":"100ml","offer_id":54912806158682,"sku":"BFH-GRN-BLK-100ML","price":40.0,"currency_code":"GBP","in_stock":true},{"title":"250ml","offer_id":54912806191450,"sku":"BFH-GRN-BLK-250ML","price":70.0,"currency_code":"GBP","in_stock":true},{"title":"1 Litre","offer_id":54912806224218,"sku":"BFH-GRN-BLK-1L","price":210.0,"currency_code":"GBP","in_stock":true},{"title":"5 Litre","offer_id":54912806256986,"sku":"BFH-GRN-BLK-5L","price":840.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0774\/9861\/4106\/files\/rn-image_picker_lib_temp_815a87a2-8f10-4be2-a339-e28461adae47.jpg?v=1791322174","url":"https:\/\/blackflaghorticulture.com\/products\/grenade-black-natural-pk-bloom-hardener","provider":"Black Flag Horticulture","version":"1.0","type":"link"}