Hi There…… Firstly if you have an air stone in your reservoir remove it as this will increase the pH….. another option is to use a small water pump on every 2 hours for 15 mins.but neither are necessary…. If using RO water ensure 5% of the volume is tap water….. pH with you substrate in the reservoir should be 5.5-5.6…. set a little lower with the tank off and it will naturally rise to 5.5-5.6 over 24hours…… there could be many issues to what you are facing such as the complete use of the nutrient schedule/elements you are using. If you need to call the office please do so on the number on the website