Changing pH

I made 2.5 us gallons of nutrients in distilled water, then adjusted the pH. I left the water in the jug. 3 days later, I check the pH and it has gone up. Why does it do that? Should I NOT pre-make my nutrient water???? Please help me..

30 views and nobody can answer this one? LOL

Temp.,Oxygen or lack of.Were plants in the soup?When plants take in nutes it can cause the ph to change.What kind of nutes?You always make up the soup then adjust Ph

I think buying distilled water is an unnecessary expense and a lot of extra work. If your water has so much dissolved solids as to make it harmful to plants then I would get a $100 RO water filter on Ebay and use filtered tap water rather than constantly lugging bottles of distilled water around. About premixing, either make and use fresh nute water OR premix and just check and re-adjust(if necessary) prior to using, simple! Ph will change in your system as your plants absorb nutes so you should monitor and adjust as necessary there too. Good Luck!

thanks guys. sorry i forgot to mention that there are no plants in this water. I make a 5 gal. bucket of pre-made nutes so that I can top off or flush and re-fill the res. The only problem is, everytime I add nutes then adjust the pH just right, it changes in the 5 gal. bucket, usually up a bit. It's weird. I'm using Monster Grow, Monster Bloom, and Liquid Carma catalyst. Olivia's cloning gel for the clones.