Need help getting my pH to stay in the range I need it. Obviously know you have to monitor it often but it seems like I'll put some pH down in the res tank to bring it down to 5.5-6.0 and a couple of hours later it shoots back up to 7 or 8. I have two aqua stones in the tank (5 gallon bucket) and am running a Viparspectra Reflector series 600W light. Using Perfect pH (Grow,Bloom,Micro) Hydroguard and General Hydroponics pH up & down. Any help/criticism would be helpful.