Ph Dropping sign of Root Rot

[madcease]

Plants are in RDWC and are about 5 weeks veg. The first 4 weeks ph had been rising but last week or so the ph has started at 6.1 and next day was at 5.1
My res temp is at 70-75 which is pretty good and room temps dont go over 82

Im thinking this is either caused from the roots dying out. At a couple of stages for like a day or 2 the res had been over 85 because had stuffed up so the res was at about 90 as well which ccould have been the cause for root rot.

Also when using rockwool slabs and the plant is getting feed for 1min 2 times a day what i have seen is that when i flush with plain water and check the run off the ppm of the water shoot up to 1100 ppm and ph drops from 6.5 to 5. Obviously thats the nutrients in the rockwool doing this but should it hold so much nutrients? Will it cause the plant to die with these readings from rockwool. Maybe its getting overfed way to much but i have heard people feed DWC 3 times a day. BTW the rockwool never gets anywhere near dry? Should the RW get less feeds maybe once a day?

If need any more info let me know thanks

 

[Doco]

Im a little confused as to what setup you have (dwc or rockwool slabs) but 80 or 90 degree res temps are no good even for a couple days. When I noticed my ph dropping on a daily basis running a rdwc (modded waterfarm) I discovered I had developed root rot at temps around 75 -80. I dumped an entire bottle of Food Grade H2O2 into my res, which burned off a bunch of small hair roots and clogged in my pumps from bits & pieces of root - I thought I had killed my plants but they came back and finished strong. A dose of H2O2 might help - search the site for more info.

After that I ran a small water chiller - if roots are constantly suspended in the solution like in dwc, the temps MUST be below 72, preferably 68 and the reason (besides being less friendly to pathogens) is oxygen. Cooler temps = more oxygen in the solution. IMHO ANY dwc setup needs a chiller.

Wikipedia says:
In hydroponic applications, root rot can occur if the water is not properly aerated. This is usually accomplished by use of an air pump, air stones, or air diffusers. Root rot and problems with water aeration are one of the reasons that lead to the development of Aeroponics.

This is the main reason I have switched to Ebb & Grow buckets - it doesnt need a chiller since the roots are not constantly suspended in the water and the plant roots get so much oxygen they just explode with growth. Ive never had another problem with root rot since.

 

[richyrich]

Yes, that is usually the sure sign of root rot. Take a look at signature below, may help you. Best advice is to add H2O2 every day to rez until next crop then buy a chiller and add lots of oxygen.

 

[madcease]

I was going to add h2o2 but i thought maybe my case is not as bad to use that. Do i just add 5ml to the rez then feed as well?
The roots are still a creamy white colour with no brown just not bright white.

I am going to setup a chiller is it fine to run nutes through those?

Im still worrying about the amount of roots that are at the bottom of the DWC
For 6 weeks veg im sure there should be alot more than that. Can only see like 10-15 roots suspended in water. Is it because the RW is so large and roots are trapped in the RW?

 

[Doco]

Yes you can feed nutrients as normal - H2O2 turns into plain water after 24hrs and yes you can run it through the chiller. Use the Search tools to find others who have run Hydrogen Peroxide or H2O2 and what dosages they used - I overdid it myself but it worked.

 

[madcease]

Thanks thats good to know it degrades have done alot of reading but yet to see what happens after.
I added about 25ml to 40litres 3%. It seems to have worked but do i have to keep adding every few days or is this enough to kill and control?

Also with RW i am unsure of how much to feed. Have heard people feeding 3 times with dwc for 1 min each. I tried that and just think its way to much feeding and the rockwool never actually dries out.

Can a plant survive on just the DWC roots in water/nutes and give it a feed once i think rockwool is dry?

Also i have alot of my tips on the leaves curling up. May be overwatering?

 

[madcease]

One thing for sure is that a chiller does amazing things. Temp stays at 19-20 degree
If the h2o2 breaks down in 24hours should one always keep adding more to controll situation

 

[Doco]

If you have a chiller now and the temps are under control, you may not need to keep adding H2O2. Your root problems should start to clear up and Ph should start to stabilize. At least that was my experience.

In addition to killing off the pathogens, H2O2 kills off beneficial bacteria as well so you should not use it if everything else has stabilized.

I've only done one dwc run so I defer to others more experienced to answer those question but a photo would help quite a bit.

Best of luck

 

[Weedhound]

Just to add to Doco....a zyme productx such as cannazym is a great product to keep root rot at bay. Won't cure it but WILL prevent root rot in most cases. I use DM Zone and Rhizotonic to treat root rot (not at the same time.)

good luck

 

[Doco]

Weedhound? From C . c o m? Its has been a long time - great to see you here!!
You remember all the problems I had with root rot a couple years ago then - you were very helpful to me and all of the information I am passing along here, I learned from you guys. Are you still running the farms?
Smiles

 

[madcease]

What i have found is by having the temps constantly set at 20 degrees will do the following
Keep the DO at a high level for roots and also not show signs of root rot.
Also by adding the h2o2 that will help with cleaning the roots and system out of dead roots

So from now on in there should be no more problems with temps or do or root rot
But one thing is the lines going in and out are exposed to light because of clear tubing and have after 4 weeks been badly covered with algae. Going to replace all these and change with black hoses. Does algae on roots stunt a plants growth? Pretty sure it does.


Also i have chlorine in my tap water. Should i be using that water hardener they use for fish tanks to remove chlorine or is it not that much of an issue. Have seen that sometimes it can be a benefit.

Thanks for your knowledge

 

[Weedhound]

'Leave the water sitting out overnite before using it and the chlorine wil dissapate into the air over 4 or so I am told.

Doco good to see you as well. I was using H202 for quite awhile for root rot but I stopped
when I od'd some fish to whom i mistakenly added plant water and it kiled the fish overnite. Additional areation is a great idea as well.

My standard dose for h202.....store bought 3% I add 10-15 ml per gallon every other day and the strong stuff (35%) I add 2ml/gal eod.

Good luck.

 

[Proteus]

DWC is tricky.

are you using hydroton? if so, that will raise your PH dramatically until the pebbles/rocks are "seasoned." I wash my rocks well, then soak them in vinegar before use. I then wash and reuse my rocks each crop, as the yare already seasoned and stable.

root rot is why i stopped doing DWC... propensity for crop failure is high in any water system.
coco/soil much more forgiving and hard to lose your crop.

 

[madcease]

Qucik question in regards to cool tube lights
I have in out guage and i have the wire with the out prope over the shade and sitting at the top of the head. It reads about 24-29 degrees depending
Now what is the actuall limit for those temps at the tops?

Because im running 2 cool tubes and exhaust on the same centrifigal fan 250mm that the cool tubes aint sucking enuf air as when i hold it its very warm but if i block the exhaust i can lower it even more.
I try keep them about 12-14 inches because of that reason. And getting another fan is out of the question.
Just need to know temps right at head. I know canopy and room temps are around 23-25 Thanks guys.

BTW i Bought some Pysthan 20 added to rez and bought a UV sterilizer all thanks to Richyrich. Thank s bro ur the best

Why are my roots still a bit brown even adter the psythan and h202?