Kalichakra in DWC: PH rising too fast

[MoleMcHenry]

Hi MyNameisStitch and all the other helpful ICMag members. My 2 Mandala Kalichakra females have been experiencing rapid PH increases in the last 3-4 days and I could use your help getting it under control. They're just a couple weeks away from harvest. I filled out the form below, if you'd like to skip ahead...



My story
I finally got a PH pen and EC pen last week. I measured my dwc nute solution, and both were high, so I first did a 1-hour flush with GH FloraKleer. After flush, I replaced with 1.3 ec PH 5.2 solution. Checked later and it was 7.8 PH and ec had not changed, so I started a flush with PHd water and very low nutes. Today I checked at lights on and ec was about the same and PH was 7.6 or so. So an hour ago I did a switch-out with 300 PPM 5.3 PH solution. Just checked it and PH had risen to 6.8.

Any idea what's going on?

HYDROPONICS/Aero Ponics

What system are you running? 2 gallon DWC buckets
What STRAIN are you growing? Mandala Kalichakra
What was the establishing technique? Seed
What is the age of your plants? Vegged a few weeks from seed, now flowering Day 54 or so
How tall are the plants? 2.5 ft
What PHASE are the plants in? (seedling, vegetative or flower) are the plants in? Flowering
What Technique are you using? Used a little LST
What substrate/medium are you using? Hydroton and rapid rooters
What is the Water temperature? 21 C
What color are your roots? Brown
Are your roots slimy? No, but in the last couple days, there has been more root material in buckets than normal.
What Nutrient's are you using? GH Floranova Bloom with Hydroguard
How much of each if using multiple? 1/8 tsp per gallon or so. I've been flushing for the last day trying to stabilize PH
What is the TDS/EC/PPM you are using? 300 PPM
What is the pH of the "Tank"? Right now, an hour after putting in 5.3 PH water, PH is now 6.8!
Are you sure your calibration is correct on your equiptment? Just bought and calibrated my new PH pen last week.
When was your last watering? Been switching out with correct PH'd water a couple times a day the last couple days.
What is your water temps? 21 C
When was your last feeding change? (ie. grow-bloom-micro-additional) An hour ago put in tap water, very mild nutes (300 PPM), hydroguard and GH PH down till solution was 5.3
How often do you clean your system: example: Flush out water replace with clean water and nutrients? Twice a week usually
What size bulb are you using? 400 watt HPS
What is the distance to the canopy? 8-14 inches
What is your RH Factor(Relative Humidity)? very low--10 percent--I live i the US mountain west
What is the canopy temperature? 80-85F
What is the Day/Night Temp? (Include flucutaion range) keep house at 70 F, and temps inside tent when lights are on gets it to 80 F
What is the current Air Flow? (cfm etc.) Inline fan 170 CFM
Is the fan blowing directly at plants? There is a 6" AirKing circulation fan in tent
Is your water HARD or SOFT? Dunno, but it is 165 PPM out of tap
What water are you using? Tap
Has plant been recently pruned, cloned off of or pinched? No
Have any pest chemicals been used? No
Are plant's infected with pest's? Not to my knowledge

Any help is appreciated y'all. I'd hate to lose these plants, as they;re so close to harvest, and the buds still look lovely.

Cheers,
Mole

 

[MynameStitch]

If your pH is rising quickly there could be 1 of 2 things causing this, either you have root rot when your roots are brown, what color are your roots?

Another thing, you are using tap water, this is another factor, do you know your tap water PPM? EC 1.3 does not = 300 ppm.

What ppm you have in there now 300?
If your pH is rising and you have low ppm levels, this will cause them to rise as well due to the plants removing nutrients from the water quickly and this will cause a quick rise in pH.

For those size of plants you are supposed to have a higher level of ppm than 300.

Canopy temps need to come down a bit too, warmer temps will cause plants to transpire more.
Do you own pH down? If not you need to get some. RO water is nearly a must if you have hard water, not only will it cause problems with your pH rising all the time due to high levels of cal and mag, but it will end up making it harder for the plants to take in the nutrients it needs.

Root rot fungus will cause your pH to rise a lot too if I remember correctly.....
Your water temps is right on the boarder, you do not want it to go over 70F.
65 to 68F is around a good number to.

Warm grow room will cause water temps to rise, so make sure you monitor your water temps all the time.

 

[FreezerBoy]

You didn't mention what you were using to lower your pH. Was it vinegar, lemon juice or something else you found in the kitchen? All of these are great for immediate readings but, only last a few hours, requiring 2-3 adjustments per day. Phosphoric acid, aka pH down, is far more lasting.

 

[MoleMcHenry]

Thanks for the quick replies! I appreciate the help.

Stitch- Here are responses to your queries.

Roots- my roots are brown, but I use Floranova, so they're always brown. I have been using hydroguard in all res changes up to now, too.

Tap water - I do use tap water. Tap water ppm is 165 or so. Tap water is PH is 8.2-8.4 or so. Luckily this is my last hydro grow for a while; I am starting a perpetual soil sog for subsequent grows.

Nute ppm - I know I am supposed to be feeding more than 300 ppm in this late flowering stage but I was doing a flush...with very low nutes instead of no nutes. I have only been doing that since the PH problem started, or when I first started noticing it with my ph pen.

I take it from your response I should quit flushing and maintain normal ppm with PH'd nutes?

Canopy temps - I have definitely had some problems with leaf burn from my 400 w HPS in my 36x20 grow tent. Today I am receiving a 400w CMH from advanced lighting. Lots of people say CMH bulbs don't throw down as much heat as HPS bulbs, so hopefully that will help with canopy temps and overall temps, too. A possible negative is that my plants have never gotten any UVB from the HPS bulb, and the introduction of UVB with the CMH may give them sunburns...I've heard that sometimes happens, anyway.

Bucket water temps - I'll keep a close eye on these and try to keep them down in the 65-68F range.

Freezerboy - I use GH PH down to lower PH. For a week or two right before recieved my PH pen, I used white vinegar. Then I read a couple posts that said vinegar only works in soil and you have to use manufactured PH down for hydro setups.

Thanks again for your quick replies! I'll update later tonight when my lights come on.

Mole

 

[MynameStitch]

I have seen people use floranova and there roots are not always brown.

When did the brown occur?
Can you get pictures of the roots so I can see if it's nutrient stain or root rot, root rot will cause pH to rise very quickly.

Yes, with hard water you will always have problems maintaing a low pH due to hard water having a natrually high pH level.
You should be using pH down to help maintain it.

Yes, stop flushing, you should only be flushing if you are close to harvest or you need a system clean, or your nutrient solution is too strong and need a flush.

I used white vinegar. Then I read a couple posts that said vinegar only works in soil and you have to use manufactured PH down for hydro setups.

Vinegar does work, BUT it only works for a few hours in hydro, works for around a day in soil or a little longer, it's not strong and yes good call on the GH pH down.

vinegar and lemon juice is not stable and does not last long enough to stable a pH rise or fall problem.

 

[MoleMcHenry]

Hi Stitch and helpful ICMaggers,

My roots have been brown since they began living in their dwc buckets (theyve been fed floranova their whole lives), but that doesn't mean they can't also be suffering from root rot, as you mention.

Here are two pics I just took so you can see for yourself. The brown is kind of red-brown.





In addition to only using GH PH down, I've also put foil tape over the bucket tops, put in a cooler CMH bulb, and started putting frozen bottles of water in the buckets to cool them down.

All that has started to work, I think. When I checked PH, PPM, and water temps at lights on, ph was 6.1, temps were 75F and PPM was 600 in one bucket and 1300 in the other. The bucket with 1300 PPM is a bit of a mystery, as it started with 650 PPM.

Anyway, I am going to try to keep water temps down with those frozen bottles so it stays between 65-68F as you recommend.

Thanks again for your help!

Mole

 

[MynameStitch]

Dude, there is your answer right there man, that looks like root rot, not nutrient stain, as I said root rot will cause the pH to rise very quickly.

I suggest getting your plants some SM90 to rid of that problem.

You are going to have to clean out your whole system man...... h202 and water will cleanse the system out. Everything the water touched needs to be scrubed and sanitized.

After you get the sm90 I would get a clean bucket use 2 tsp per gallon of water of h202 and rip your roots in and out of the bucket real good to help rid of as much bacteria before putting them back in the system, then get your sm90 and use the dosage they give you and put it in your system with your hydroguard and your problem will be fixed ONLY If you keep them temps down, if you keep the temps in check the sm90 will prevail, otherwise the bacteria will breed again and will overrun anything you have in there to protect them.

The rot coats the plants roots not allowing them to breath and thus slowly shutting down the plants defense and then the plants lose :*(

How often do you change your systems water?

The bucket with 1300 PPM is a bit of a mystery, as it started with 650 PPM.
If the buckets started with a lower ppm and it raised, then had to be the bacteria, cause that is the only logical explanation for that, if you did not add it, how did it get there?

 

[MoleMcHenry]

Stitch - Thank you so much for your help. I'll get some SM 90 tomorrow at the grow shop!

 

[DIGITALHIPPY]

stitch is right on every button....
also.. need to probably give them an extra week to recover.. they should be ok.

i agree by the pics i c rot..

plant top looks good overall though, your plant did not get to the whilting stage, thats good.

sm90 is a great product. sometimes hard to get, i thought the hydroguard would have helped, but heat will help the rot...

i saw in the second pic the frozen waterbottle thawing in the res... good start.
dip the roots in h2o2 and water maybe even 2 or 3 times, like stitch was saying the bacterial will hide good. i can thelp but think her dilution ration for h1o1 : h1o is weak, ive put nearly 10x that with no problems... dont have to though.

h2o2 might make your plant greener as the oxygen level is higher....
also try adding a airstone to your bucket, will help keep DO levels, up your plants are monsterous.... have big needs...

 

[MoleMcHenry]

Thanks for the advice and kind words DigitalHappy.

I've been keeping temps and PH stable, and last night did a hydrogen peroxide wash/repeated dip of the roots. Today I got some SM-90 from my local grow shop and used it as soon as I got home. Based on your advice, I'll give the girls a second peroxide wash tonight, along with res/bucket changes.

I hope they get better soon. There's not much time left before the harvest--just a couple weeks--and they are lagging in bud/resin production. Their PPM's haven't gone down in over a week.

Mole

 

[MynameStitch]

Ya, they don't take in the PPM's due to there roots being affected, they coat the roots cutting off air and the amount of nutrients they take in. It's like us when we have the flu we can't eat a lot of times and get sick, same goes for the plant.

 

[MoleMcHenry]

Based on DigitalHappy's advice, I gave my sick girls another bath in hydrogen peroxide last night and changed their buckets with fresh nutes/sm90. I'll give them another peroxide bath and nute change/SM90 tonight. Water temps are under control and PH is under control 12 hours a day, when I can get in the tent. Roots on both girls are getting more white and less red-brown, though one is definitely more white than the other.

Fifteen minutes ago I checked them and PH was 6.8 or so and PPMs were unchanged. I adjusted the PH then started getting a little worried, almost like they are loved ones.

Anyone know when I should expect them to start showing signs of recovery?

 

[icough2getoff]

Those treatment solutions are helpful for cleaning up some root rot and healthy roots but you need to fix the source of the problem, and not expect to solve your root rot with the additives. If your temps are below 70°F then I would add another air pump as mentioned.

For the ph issues I'd recommend getting a reverse osmosis filter or check/adjust your ph twice a day. Another option but pricey would be something like a ph nanny

 

[MynameStitch]

His problem is not with his water, but his temps as I know you know this, RO will help control the pH, but his pH rising is from the rot not from using tap water.

 

[Praxis]

So you can use hydroguard and sm90 together? I thought (well read..) that sm 90 kills all good bacteria so.. im confused.
Does sm90 kill organic stuff so no go with pbpgrow?

Can to much hydroguard cause the ph to rise? Sorry for all the questions but saw this thread and am having simular problems.

 

[MynameStitch]

Never heard of that before praxis, sm90 is organic......
now h202 does kill the good bacteria and bad bacteria; never heard of sm90 doing that; I can find out; but I am sure it does not.

hydroguard is safe to use with sm90.

not sure about using too much would cause it to rise, will check on that as well.

But if you read my posts in this thread you will find out what causes the pH to rise.

 

[Praxis]

Check this out its from this thread (good read imo), http://www.icmag.com/ic/showthread.php?t=5903

Cautions

SM-90 is a great solution additive to discourage pests and fungal disease and other bacterial pathogens. It is

however for this reason that it is not particularly advantageous in organic soils or solutions because it can inhibit

beneficial bacterial colonization. If you are trying to promote bacteria growth this is probably not a desirable

additive.

Let me know what ya think.

 

[medmaker420]

do you have a full pic of your tent setup? inside with the light/fan/plants to see how you have them in there. I got a 36x20x62 tent and have a 400 on the way. Hoping to get 6 in there (soil) but not sure on the room in there.

I am thinking of doing something very similar and wanted to see how well everything fit in.

sm-90 for sure..

root rot is a pain, did you get it all ironed out