There is no such thing as an ideal pH. High values help cation uptake and low values help anion uptake: every fixed pH is a compromise. The usual safe range recommendation is from 5.5 to 6.5. Our advice is to stay on the low side: from 5.5 to 6.2.
GHE pH -: 
Premium pH management and buffering for hydroponics, coco and soil.
Not just a simple acid: GHE pH - makes a real contribution to nutrient solution stability
To make GHE pH - we carefully blend three acids commonly used alone in hydroponics to give you all the benefits of each - without the disadvantages.
GHE pH - uses nitric and phosphoric acids to do the initial heavy lifting of altering your water pH, and the blend of both means no disturbance to your N/K ratios throughout grow and bloom - and no residue on the surface of your tank from using phosphoric alone in hard water areas. Then, with its own special characteristics, organic citric acid takes over to buffer pH changes over time, keeping your nutrient solution more stable, and helping handle calcium excesses in hard water areas.
 
GHE pH +:
Premium pH management and silica source for hydroponics, coco and soil.
Control pH and boost silica levels at the same time
Whilst raising pH level may seem crazy to growers in hard water areas, it’s a real issue with very soft water or when using reverse osmosis. GHE pH + allows that adjustment, and offers a good source of available silicate - which is often deficient in Hydroponics, due to its very low solubility. Proper silicate levels make a big contribution to plant health and so we include it in products whenever we can