PH questions

[jimmyjoe]

Ok, I have a 7 gallon hydro system. i added the ph adjusted water (6.0 ph) to a newly cleaned and sterilized system and check the ph 24 later and it is 7.3. So I decide to check things out. I get a 2 gallon bucket of water, add nutes and adjust ph to 6.0 and test 1 hour later to confirm, still 6.0. I take the bucket to my grow room and put it in the corner of the room covered. I check the ph in the bucket 24 hrs later and the ph is 7.0. I had to add 40% more ph adjuster to bring the 2 gallon bucket to 6.0.
My questions are...has anyone else experienced this? and do people think I should add the extra ph adjuster to bring it down to 5.2 -5.5 and let it rise in the system to 6.0?
Any info is appreciated. BTW, I had just moved clones to veg 2 days ago which is why I cleaned the system,

[Tersky]

Did you put air stones in the 2 gal bucket? I have never heard or seen where a plain bucket of nutes with no air stones in it fluctuate for no reason. The agitation of air stones can change ph so if it is changing cause of air stones then lower the air pump pressure so it doesnt agitate so much. Also what are you using to adjust ph? Some ph adjusters have a short half life meaning they dont last very long. Third what water are you using? I found my tap water difficult to change ph but RO or distilled water fluctuates too easily so i use a mix of tap and RO.

[jimmyjoe]

No air stone, using a MEGA MASS ph down product which has a decent rep. Using Tap water.

[Tersky]

i found i had issues with my tap water having a stable ph as well. What i found that works is mixing RO and tap. I feel as my county put something in the water to keep it at around 7 or higher a few years ago cause i had a hell of a time keeping my ph low. I got an RO kit and found that straight RO water was around 6.0 which was perfect but the problem was that there was nothing in the water to keep the solution stable even after adding cal mag and nutes. I found in my case that 75% RO and 25% tap (or 3:1 RO:Tap was a ratio that provided stable ph values. I dont know if that is what is happening in your case but it kinda reminds me of my circumstance. Even try getting filtered water from the store and test several different types to see if the issue is tap water related or not. Unfortunately i dont know about mega mass as i use GH ph up and down so i cant give any advice about that. This is a weird one. It seems as if there are either weird buffers in your tap water like i suspect mine has or something is changing in your nute solution. It could be organic matter eating at the nutes and changing the ph that way or something in the nutes is not stable and is decomposing strangely fast making the ph change. I have noticed that a gallon jug of nutes for me stays pretty consistent for at least a few days and then slowly changes but a 24 hr flux like that is strange. You mentioned that you cleaned your system so i am hesitant to call it organic in nature..sorry if my answer is not that helpful but so many factors can be at play in hydro setups it's hard for me to be sure what it is so i am just throwing ideas out.

[jimmyjoe]

thanks for your input