So I assume you have a Ph meter as you know the level of your water. Whether you are watering with just the water or with nutes added, you can add Ph down to the solution and mix it in before watering your plants. Word of warning, Ph down is acid and is some strong shit so please try not to get any on your bare skin and if you do, wash your hands immediately. So in line with that, only add a tiny amount to your water, mix it well and test the Ph level. If you need to add a drop more to get to your desired number, then do so. But as I say, just a drop at a time as it is very strong and will bring a Ph down quickly. It is always easy to add more if you need to, but impossible to take out if you put too much in. Drops my dude, drops!!!!!