Thankls for the reply man! it actually helps....now that you mention it, iv been using a pH of 6 but hav found thaT over time it increases???? Now im using a system that flood and drains every three hours (what can i say...im a lazy gardener! ) but logically i presume its bcoz it recycles the liquid that already in the pods. Is this a problem? do you think i should use a lower pH to compensate for this? I appreciate the advice. SAFE!!!!!