{"product_id":"growth-technology-ph-down","title":"Growth Technology pH Down – 30% or 81% Phosphoric Acid","description":"\u003ch2\u003eGrowth Technology pH Down – Because Nutrients Only Work at the Right pH\u003c\/h2\u003e\n\u003cp\u003eYou can give a plant the finest feed money can buy and still watch it go hungry. If the water's pH is wrong, nutrients lock up in forms roots simply can't absorb: iron, calcium, magnesium and phosphorus are first to go. Most UK tap water comes out of the tap too alkaline for plants to feed at their best, and in hydroponics, coco and semi-hydro the pH tends to keep rising day by day. pH Down brings it back into the zone where every nutrient is available.\u003c\/p\u003e\n\u003cp\u003eGrowth Technology pH Down is made from \u003cstrong\u003ephosphoric acid\u003c\/strong\u003e, one of the most stable and widely used pH adjusters in horticulture. It's a little nutrient as well as an adjuster, since phosphorus is something plants use.\u003c\/p\u003e\n\u003ch3\u003e30% or 81%?\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eStrength\u003c\/th\u003e\n\u003cth\u003eBest for\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003epH Down 30%\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eGentler and easier to control: ideal for small reservoirs, watering cans, semi-hydro and houseplants, or anyone new to adjusting pH\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003epH Down 81%\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eHighly concentrated: best value for bigger tanks and experienced growers, as a few drops go a long way\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003eBoth are phosphoric acid. The 81% is simply far stronger, so start with tiny amounts.\u003c\/p\u003e\n\u003ch3\u003eTarget pH\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eHydroponics and semi-hydro (LECA, pon):\u003c\/strong\u003e 5.5–6.2\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCoco coir:\u003c\/strong\u003e 5.8–6.2\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSoil and compost:\u003c\/strong\u003e 6.0–6.5\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eHow to Use\u003c\/h3\u003e\n\u003col\u003e\n\u003cli\u003eMix all your nutrients and additives into the water first.\u003c\/li\u003e\n\u003cli\u003eStir, then measure the pH with a meter or test kit.\u003c\/li\u003e\n\u003cli\u003eAdd pH Down a few drops at a time (use a syringe), stir well and re-test.\u003c\/li\u003e\n\u003cli\u003eRepeat until you reach your target. Recirculating systems may need checking daily, as pH drifts upwards.\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp\u003eGrowth Technology recommend that if you dilute pH Down 30%, a 1 in 10 dilution is ideal (500ml in 5 litres).\u003c\/p\u003e\n\u003ch3\u003e⚠️ Safety\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eDANGER – causes severe skin burns and eye damage.\u003c\/strong\u003e Both strengths are corrosive phosphoric acid. Wear gloves and eye protection, keep out of reach of children, and never mix pH Down with pH Up, or with any concentrated nutrient. Store acids and alkalis separately. A safety data sheet is available from Growth Technology.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e🌿 Rose's Pro-Tip:\u003c\/strong\u003e always adjust pH \u003cem\u003elast\u003c\/em\u003e. Every product you add changes the pH, so measuring before everything is in is wasted effort. And use a syringe, not the cap: with 81% especially, the difference between \"perfect\" and \"overshot\" is a couple of drops.\u003c\/p\u003e\n\u003ch3\u003eSizes\u003c\/h3\u003e\n\u003cp\u003e30% and 81% in 250ml, 1 Litre and 5 Litres, plus a measuring syringe.\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003eBlack Flag Horticulture Ltd, Coventry – genuine Growth Technology stockists.\u003c\/em\u003e\u003c\/p\u003e","brand":"Growth Technology","offers":[{"title":"250ml \/ 30%","offer_id":54350501249370,"sku":"GT-PHD30-250","price":9.09,"currency_code":"GBP","in_stock":true},{"title":"1 Litre \/ 30%","offer_id":54350501282138,"sku":"GT-PHD30-1L","price":12.79,"currency_code":"GBP","in_stock":true},{"title":"250ml \/ 81%","offer_id":54350505115994,"sku":"GT-PHD81-250","price":9.28,"currency_code":"GBP","in_stock":true},{"title":"1 Litre \/ 81%","offer_id":54350505181530,"sku":"GT-PHD81-1L","price":16.68,"currency_code":"GBP","in_stock":true},{"title":"Syringe \/ Measuring","offer_id":54351062925658,"sku":"BFH-GTPHDOWN-SYRNG","price":3.99,"currency_code":"GBP","in_stock":true},{"title":"5 Litres \/ 30%","offer_id":54369091420506,"sku":"GT-PHD30-5L","price":38.16,"currency_code":"GBP","in_stock":true},{"title":"5 Litres \/ 81%","offer_id":54369091453274,"sku":"GT-PHD81-5L","price":63.52,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0774\/9861\/4106\/files\/rn-image_picker_lib_temp_da1496d9-e68c-44c0-9c44-30921b47b1e8.png?v=1789918176","url":"https:\/\/blackflaghorticulture.com\/products\/growth-technology-ph-down","provider":"Black Flag Horticulture","version":"1.0","type":"link"}