Problem with Ph fluctuation in DWC Standalone Buckets

[MasterChief]

My background in growing goes back two years, so far all of my experience has been in organic soil. I finally decided to try out hydro and so far its been a headache :worried

Sealed room, Co2, dehumidifier 50-60% temps ~70F

Strains: (1) Purple Kush (1) Deep Purple

Setup: (2) Standalone DWC Buckets, Hydroton

Started by PH buffering the hydroton in a mild nute solution, sat in a 5gal bucket for almost three days, ph seemed to stabilize so I decided to put the girls into the buckets.

These past two days I have been having a very hard time keeping the ph at 5.5, I will adjust the buckets to 5.2 and it will jump up to 8!!

Nute solution: 5 gal clean water, cal-mag to 140ppm, canna aqua vega part a and b 10ml each to 450ppm, 9ml per gal of cannazym, and 15ml per gal of rhizotonic.

I noticed some gunk building up in the buckets earlier, and also spaced on cleaning them before putting the girls in. So I took one out at a time, put her in ph'd clean water. I began cleaning the buckets, first with warm soapy water, then I let them sit (including the air stones and air lines) in ph'd water with H2o2 @ 1 teaspoon per gal for about 45min, then rinsed with hot water thoroughly.

After cleaning the buckets...

I gave them new nutrient solution at 9:28pm and set the ph at 5.2 and now (10:51 pm) one bucket is at 6.1 and the other at 5.7. So in one hour and 23min the ph has jumped up quite drastically.

I'm finding that every two hours I have to adjust the ph.

Are dwc standalone buckets like this? The guy at the local shop told me that canna aqua tends to fluctuate in ph a lot in the first 48hours but will taper off eventually and stabilize.

How are you guys setting your ph?

Somehow I am baffled that these girls aren't looking worse than they are. Starting to show deficiency but I have a pretty good guess as to why....

 

[Seamaiden]

I don't do full hydro/Hydroton, but off the top of my head you said "clean water", which doesn't imply the cleanest possible water. It may be filtered tap, but if it's tap then very likely it's alkaline (pH buffering capacity) and if that's the case, you're going to have a very hard time controlling pH bounce.

This will serve more to bump to other, more experienced farmers.

 

[MasterChief]

I do agree with you that tap water may effect PH, but this morning I checked the ph and one bucket was 8.8 and the other was 9. My tap water usually measures around 7.8, the hydroton is ph buffered to 7, so I have absolutely no clue as to why the ph is going over 8? Something in the system is doing a great job at sucking up all the free ions.

I am using earth juice as my PH down (citric acid), I've read that this maybe the issue, i'm going to my local shop to try a different ph down.

 

[Dr. Detroit]

Many times if you're using municipal water what seems to be a pH related issue is in actuality salt accumulation.

What are your ppm or ec readings after adding your nutrient solutions? Would you drink your own tap water, or is it too hard?

 

[MasterChief]

The water out of the tap comes from a nearby lake reservoir, my blue lab EC pen does not get a reading from the water so it is below 100ppm. My TDS pen (conversion factor 500) read the water at 60ppm, so no my water is not hard. And yes I drink it everyday.

After adding rhizotonic and cannazym the ec is around 0.8.

This morning I checked the buckets, one was at 8.8, the other at 9.0 :worried

I am using earth juice (citric acid) to buffer the ph, from what I have read citric acid doesn't work well in dwc systems. I went to the store and grabbed some general hydro ph down.

I cleaned the buckets, changed the nute solution out with something a little milder (less rhizotonic) and used GH ph down, set one bucket to 5.2 and the other at 5.3, it is now 2:28pm, we'll see what happens in a couple of hours.

 

[MasterChief]

Changed PH Down from Earth Juice (citric acid) to General Hydro

General Hydro Ph down seems to be working a lot better at keeping the ph down, so far the highest the buckets read today was 5.8 :)

 

[Seamaiden]

Fantastic! That's almost no bounce at all. Here's to hoping it remains stable.

The water out of the tap comes from a nearby lake reservoir, my blue lab EC pen does not get a reading from the water so it is below 100ppm. My TDS pen (conversion factor 500) read the water at 60ppm, so no my water is not hard. And yes I drink it everyday.

Wow... ok, so it's more like your source water has NO alkalinity (resistance to pH shift). I honestly can't answer why it's bouncing up so high, I mean those numbers you're posting below are almost astronomical they're so base. If this were an aquarium I could totally help you, I'm really sorry I don't have any answers because I've never used this growing method. That said, I think Dr. Detroit is onto something, although salt accumulation tends to force pH downward, not up.

After adding rhizotonic and cannazym the ec is around 0.8.

This morning I checked the buckets, one was at 8.8, the other at 9.0 :worried

I am using earth juice (citric acid) to buffer the ph, from what I have read citric acid doesn't work well in dwc systems. I went to the store and grabbed some general hydro ph down.

I cleaned the buckets, changed the nute solution out with something a little milder (less rhizotonic) and used GH ph down, set one bucket to 5.2 and the other at 5.3, it is now 2:28pm, we'll see what happens in a couple of hours.

Will be curious to see what happens. Strongest pH adjusters I've used to date are the AN products.

 

[Dr. Detroit]

With excessive sodicity or salinity all of your problems seem to be nutrient-related. I'd say that the above response that it could be an issue with your pumps or hoses could be apt. With the pumps being (usually) at the bottom of the feed tank they tend to accumulate the most sediments over time. A changeout or a hard flush of your whole pump system could be beneficial if your issues are not already resolved.

Just two more questions: Do you aerate your water, and are you East or West of the Rocky Mountains?


Don't know if this link will work:

http://books.google.com/books?id=II...=onepage&q=alkaline salt accumulation&f=false

 

[MasterChief]

The air pumps sit outside of the res? so no that isn't my problem....And in my post earlier everything that is inside the bucket was cleaned with water + soap and then cleaned with water + h2o2. I also ph buffered the air stones and air lines.

I reduced my rhizotonic down to 2ml per gal, this seemed to be the cause of the frothy build up. I was def way to high at 15ml/per gallon.

Set the buckets up last night at 12am at 5.4 and 5.5.....

Checked the buckets today at 11:30am...... 5.9 and 6.0!!!!:icon_spin:

Canna is good up to 6.2!!

My deep purple pheno grew into my ghetto bank !!! and I noticed some root growth on top!!

So far I believe all the cause of my problems was the citric acid, it is not a sufficient enough buffer to keep the ph levels low enough in a hydro system.

Buffering capacity of citric acid

While General Hydro PH Down Contains phosphoric acid, citric acid and mono ammonium phosphate which, is much more capable at buffering the nutrient solution.

 

[Seamaiden]

Dr. D, for the rest of us, why do you ask re: east or west of the divide?

 

[MasterChief]

After a couple days I can definitely say that my problem was my ph down. Citric acid does not work in hydro. If other people are having problems with ph fluctuation I would start by changing your buffering solution.

Now, I can set the buckets to 5.5 before I go to sleep, and 24hrs later the ph is up to 6.2. So it isn't as annoying as having to set the ph multiple times a day but to me that is high maintenance.

 

[Dr. Detroit]

Dr. D, for the rest of us, why do you ask re: east or west of the divide?

Well, my mother is a baker, and through her I learned that the watershed West of the Rockies tends to be very alkaline. I was complaining a while back about the low quality of baked goods in California (especially bread), and she mentioned that the high pH of our water is the cause.

The water here has both high salinity and high sodicity, along with incredibly high dissolved solids. Water in the West (through my own testing) has shown itself to be about twenty or thirty times higher in saline than the water back in Michigan.

I had a lot of frustrations over what appeared to be pH adjustment issues for a while, but once I realized that salt accumulation from my watersource was the true culprit there have been no problems at all. The problem is only exasperated by using mineral salts in hydroponic setups.

 

[Seamaiden]

Wow! I've not spent much time east of the divide, and when I did it was the deep south (child). I've just learned something entirely new today. Thank your mom for me!