Rapid pH down

[Spanky84]

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?

 

[k_elliott99]

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

 

[_MrBelvedere_]

https://www.rollitup.org/t/newbiequickstart-bulletproof-guide.864600/

 

[Spanky84]

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

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]

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?

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?

 

[Spanky84]

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 :/

 

[churchhaze]

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.

 

[sqlb3rn]

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.

 

[Spanky84]

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.

It's heavily coloured, but clear-ish.

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

 

[Spanky84]

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.

It's not root rot. Too much root growth and no slime. Fulvic is safe for hydro BTW. Microorganisms can't eat it.

 

[sqlb3rn]

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]

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.

 

[Spanky84]

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.

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]

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]

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??

 

[Spanky84]

New regime is in place, res is now changed every 3 days. It seems to be helping.

 

[kupihea]

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??

Super, I'll go for it!

 

[redi jedi]

Whens the last time you calibrated your PH pen?

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

 

[Spanky84]

I checked it few days ago. It's OK.

Yes, micro.