Why is my ph slowly dropping after few days of reservoir change?

projectinfo said:
What would be the isse if the planta are drinkin more water than nutes?

Ec too high?
Click to expand...

I'm no expert, remember that, just a dude with a few grows under his belt.

If they're drinking more water than nutes, then as the res level lowers the remaining solution will drop pH and the EC will go up.

If they're taking in more nutes than water, then as the res level falls then the solution will raise in pH and the EC will drop.

If it's in balance, the solution won't drift very far in either direction as the level drops, which isn't necessarily ideal because a swing in pH is good for a variety of nutrient uptake at various pH range

I ran a sterile res, nothing but GH 3 part and water. When I was running hydro I had to find near that balance point, and when I did it was set it and forget it.

I only changed the res once when I flipped to flower, not every week like the OP. I would top off the res with water (I had a fill-line), which dilutes the solution. I premeixed the nutes in a bottle, and would titrate them in until I reached the desired EC, then I would adjust pH if necessary, super easy.
 
When I do a res change the ph will rise for the first few days but as the ph rises above 6.5 I correct it. After 3 or 4 days is when the ph will start dropping. The plant is drinking a lot of water just eating really slow. Ppm is at 270 should I continue to lower? Btw this plant is 5x5 it’s pretty big
 
anyone think it might be a nutrient lockout? I just changed my res and have 80 ppm but ph is still dropping and ppm is staying steady. Would nutrient lockout have anything to do with ph dropping?
 
best advice i ever got for hydro:
see a problem, flush for 24 hours with RO or distilled water, start back at light nutes and raise as needed.
 
Are you taking care of your ph meter? Is it a good one?
This here is a good one
images.jpg
Using ph up/down and or poor maintenance can mess with a ph pen probe
 
I use a pen meter and also double check with the ph test kit. The plant looks great just very slow growth and she isn’t eating but still drinking a lot of water. I have a 1000 watt hps and I am in flower and don’t see much growth at all. I have always heard of the ph drops something is wrong in the root zone but I’m not sure what else I can do at this point
 
Vader og, oceangrown genetics, solved my problem. I was getting to much air into the system. I removed a air stone and one of the air pumps and within 15 min ph began to rise and plant is eating. Thought I would share this with everyone so if anyone else runs into the problem they’ll be able to try this to fix it! Cheers guys
 
Dailypunch21 said:
Vader og, oceangrown genetics, solved my problem. I was getting to much air into the system. I removed a air stone and one of the air pumps and within 15 min ph began to rise and plant is eating. Thought I would share this with everyone so if anyone else runs into the problem they’ll be able to try this to fix it! Cheers guys
Click to expand...

I find that very strange. I've been doing DWC for almost 20 years and never ran into air volume having any effect on pH. For years I used a small air pump with a 12" stone in Rubbermaid tubs then got larger pumps and went to two stones. I would set my pH at around 5.5 and over three days it would rise to 6.2 or so and I'd knock it down to 5.5 again with conc. sulfuric acid. Then I got pH Perfect nutes and retired my pH pen. :)
 
Dailypunch21 said:
anyone think it might be a nutrient lockout? I just changed my res and have 80 ppm but ph is still dropping and ppm is staying steady. Would nutrient lockout have anything to do with ph dropping?
Click to expand...

Nutrient lockouts usually happen when the pH is too far out of range and mainly affects micronutrients that cause problems with new growth.
 
OldMedUser said:
I find that very strange. I've been doing DWC for almost 20 years and never ran into air volume having any effect on pH. For years I used a small air pump with a 12" stone in Rubbermaid tubs then got larger pumps and went to two stones. I would set my pH at around 5.5 and over three days it would rise to 6.2 or so and I'd knock it down to 5.5 again with conc. sulfuric acid. Then I got pH Perfect nutes and retired my pH pen. :)
Click to expand...

i was thinking if he was using CO2 but that would lower pH
i've never had my pH rise unless I added tap water
 
fridayfishfry said:
i was thinking if he was using CO2 but that would lower pH
i've never had my pH rise unless I added tap water
Click to expand...

I never used anything but distilled or RO water but tap water often rises even after dropping with pH down due to unreacted carbonates in the water. My tap water comes from a dugout on my property and is around pH 8 and 400+ppm so it's crap.

My procedure was to top up the water then allow to mix for an hour or so then test pH and ppm. The ppm was always lower and the pH was always higher. Then I would add small amounts of nutes to raise it back up to my target ppm and add a few drops of acid to bring down the pH. If it went to low I'd just leave it and it would get back up to the mid 5s by the next day. Never seemed to go over 6.3 so that must be the buffer level of the older AN nutes. Started using the pH Perfect ones a few years ago and never worry about pH now. RO or distilled water has no effect on pH as both are neutral. They just take on the pH of whatever is added to them.

Takes a lot of CO2 to make the pH go down and the acid that is formed doesn't stay acid for all that long. Putting pure CO2 through the stone will screw things up tho. A poster years back figured the plants would do great with added CO2 to his DWC as it worked in the air. No amount of logic could convince him otherwise and he killed his 8 plant RDWC in a week. Never saw him in that forum after that. Think he joined a monastery or something. :D
 
I have an idea rattling around about bottled O2 bubbles for hydroponic solution. I'm yet to get an answer. I do know that if it were to be done it'd have to be in an unoccupied building with a fire suppression system. I have my suspicions that old-timer commercial growers did this from the photo results which are insane compared to just near-perfect environment and CO2.

I see marketing for hydrolysis "oxygenation". they taught me in chem to not breathe hydrolysis specifically with ionic solutions involved
 
bottled oxygen will allow for fast explosive combustion. If you have oxygen tanks for acetylene cutting and you're doing it inside there are regulations. regulations unlike cannabis laws. One example is a little oil was accidentally in a oxygen tank flow regulator which acted as fuel and caused an explosion which killed the guy. that's the construction way, not sure how the hospitals do their thing.
 
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