I'm starting my grow very soon, I'm growing in coco coir and using Hesi coco nutrients, I don't really want to buy a digital pH meter as they are too expensive and a bit of a hassle. But I've found these on ebay 100 Strips, Alkaline pH Test Strips Kit 4.5-9.0 Saliva & Urine | eBay Photo: Will they do the job? they can measure 5.75 which is pretty close to 5.8 which I've been told is the best pH for coco. Any advice would be appreciated!