Rapid pH down

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Spanky84

Active Member
I'm on my second hydro grow. I have done quite a lot of research and usually know what I'm doing. My plants are in 5 gallon buckets, water temps are in check (about 19C), I'm running advanced hydropinics synthetic nutes (european brand, as far as I see not very comon in USA) at about 1100 uS EC. I brew EWC tea and add fulvic acid.

My problem is, since my plants grew bigger, few days after a res change, pH would start dropping quite rapidly (from 6.0 to 5.0 or less in a day). I adjust it daily using KOH, but it drops again in a day. Plants drink a lot, but EC does not change, so I don't think I'm not adding enough nutes. I suspect it is for some reason caused by a quite large rootmass in a relatively small 5 gal bucket (although last year I had similar sized plants and not so much pH problems), but I'm near the final stages of the grow so it would be very inconvenient if I had to change everyting now in order to fit some larger buckets. Does anyone have any sugestions on how to keep pH stable and what might be causing the issue?
 
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Spanky84

Active Member
k_elliott99 said:
I'm having the opposite problem. 5.5 and a day later 6.5 and I'm on day 45 flower and its drinking 5+ liters a day! Good luck
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I know. I get the same first day after res change. I heard somewhere that funghi do that. Usually on day 2 or 3 it begins dropping.
 
mmjmon

mmjmon

Well-Known Member
Spanky84 said:
I'm on my second hydro grow. I have done quite a lot of research and usually know what I'm doing. My plants are in 5 gallon buckets, water temps are in check (about 19C), I'm running advanced hydropinics synthetic nutes (european brand, as far as I see not very comon in USA) at about 1100 uS EC. I brew EWC tea and add fulvic acid.

My problem is, since my plants grew bigger, few days after a res change, pH would start dropping quite rapidly (from 6.0 to 5.0 or less in a day). I adjust it daily using KOH, but it drops again in a day. Plants drink a lot, but EC does not change, so I don't think I'm not adding enough nutes. I suspect it is for some reason caused by a quite large rootmass in a relatively small 5 gal bucket (although last year I had similar sized plants and not so much pH problems), but I'm near the final stages of the grow so it would be very inconvenient if I had to change everyting now in order to fit some larger buckets. Does anyone have any sugestions on how to keep pH stable and what might be causing the issue?
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Uh... Yea.... Uh... I'm just here to see the rootball. heh heh.
No, so.... wait, yea... I wanna see a pic of the rootball. hehe

What is your plant looking like? Healthy?
:peace:
 
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Spanky84

Active Member
Sorry, I'm too paranoid to post pictures. But it's one massive rootball. Plants look quite well, but one has started developing bit of spots on few leaves. I'm switching to res changes every three days, and see if that helps.

Damn, I should have planned for larger buckets :/
 
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churchhaze

Well-Known Member
Is the water clear or cloudy when you drain it? If it's clear, your nutrients are probably low in potassium, and loving the KOH. When it uptakes a K+ ion, it replaces it with a H+ ion, lowering the pH of the nutrient solution. You can put it back again using KOH. If that's the case, your base nutes is likely low in K.
 
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sqlb3rn

New Member
usually indicates root rot... probably from the fulvic acid (organic) or making the tea wrong. ph usually raises a day or two after changing the res.
 
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Spanky84

Active Member
churchhaze said:
Is the water clear or cloudy when you drain it? If it's clear, your nutrients are probably low in potassium, and loving the KOH. When it uptakes a K+ ion, it replaces it with a H+ ion, lowering the pH of the nutrient solution. You can put it back again using KOH. If that's the case, your base nutes is likely low in K.
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It's heavily coloured, but clear-ish.

That's a great idea about missing potassium. Thanx!
 
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Spanky84

Active Member
sqlb3rn said:
usually indicates root rot... probably from the fulvic acid (organic) or making the tea wrong. ph usually raises a day or two after changing the res.
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It's not root rot. Too much root growth and no slime. Fulvic is safe for hydro BTW. Microorganisms can't eat it.
 
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sqlb3rn

New Member
Root rot does not always produce slime fyi, usually they just turn brown and mushy. The couple times I have actually seen slime, the ph was going up anyway.
 
kupihea

kupihea

Well-Known Member
Thanks everyone. My problem also. This is my first DWC. Large roots, 5 gallon bucket with an additional water temp issue. 73 - 77 F or 32- 25 C. I feel my issue is temperature and just want to keep things healthy till they finish. We're in week 9 and the plants look well with nice frosty tops and healthy looking leaves. It's just that pH drops daily and the roots look beige. I'm really looking just to avoid a sudden crash before this run is finished.

Living in a warm climate I'll have to address water temperature next time. I will also switch to 30 gallon container.

Any further comments and discussion will certainly be appreciated.

Oh yeah one other thing. It seems like leaves and smaller branches are weak and break rather easily.
 
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Spanky84

Active Member
sqlb3rn said:
Root rot does not always produce slime fyi, usually they just turn brown and mushy. The couple times I have actually seen slime, the ph was going up anyway.
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Well, anyway plants that suffer from root rot dont' drink up to 2L water a day and grow rapidly both under the surface and above.
 
k_elliott99

k_elliott99

Well-Known Member
I'm like u I'm just trying to finish my grow, pH for me goes up a full number everyday and my 2 girls drink 4-5 liters a day
 
nameno

nameno

Well-Known Member
Don't wait till next time to address the temp issue if you want a good finish,drop a frozen 16oz water bottle in the bucket.It will work,I been doing it over 5 yrs.
Now I'm having the opposite problem,it's going up??
 
kupihea

kupihea

Well-Known Member
nameno said:
Don't wait till next time to address the temp issue if you want a good finish,drop a frozen 16oz water bottle in the bucket.It will work,I been doing it over 5 yrs.
Now I'm having the opposite problem,it's going up??
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Super, I'll go for it!
 
redi jedi

redi jedi

Well-Known Member
Whens the last time you calibrated your PH pen?

1100 EC? Thats 5500-7700 ppm? Or does "us" EC mean micro?
 
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