What to do for root rot in rockwool

What’s the best way to diagnose and treat root rot in Rockwool cubes. My plants are in the third week of flower and for the last ten days or so they have been slowly dying. I don’t think it’s nute burn or a deffiency. The tent as gotten to about 85 a few times and I’m thinking the temps may have started root rot. How to you tell in Rockwool if this is what’s going on? What can I do to save them?

Pics man pics.

Does it stink in a gross way
Are roots slimey brown or fall off easily?

85 a few times shouldnt hurt too bad i could be wrong though

Here are some pics. I don’t know how to look at the roots In Rockwool. I’ll try to smell them and see on that.

You should have roots coming out of the bottom
Can you slightly lift a block to look?
They would be brown and slimey

i have never grown like that but all i can think of is H202 for added oxygen and to sterilize the rock wool

You mentioned rockwool, are these hydroponic grown?
Are you by chance using any beneficial microbes?
Aside from the temps, do you have any other factors that would promote root rot?

I ask because root rot usually requires a catalyst.

Edit:
Factors affecting root rot probability;
1) Low root-zone oxygen saturation
(from like over-watering in soil or inadequate reservoir aeration in hydro)
2) High (Warm) root-zone temps
3) Cross contamination (root rot is also airborne)
4) Previous Microbe colonization

Thanks for the help everybody. I think it’s a combination of things. I got some bad advise and didn’t research Rockwool specifically enough. I’m pretty sure it’s root related. All of the plants are affected differently so the root problem makes sense to me. I was not aerating the reservoir. Big mistake. The cubes are covered in algae which I think is taking what oxygen the cubes were getting and I was more than likely way overwatering. I cut the nutes in half. Added air to the reservoir. Added Hydroguard and covered the cubes to hopefully kill off the algae.

Let me know what you guys think

It looks like you block is just sitting flat on your tray
which might be drowning out those roots since the bottoms of the blocks have a lot of water weight it makes it seal too tight for air at the base if that makes sense...

Try elevating the roots on some kind of spacer that allows a little air flow . 1/2 or so that will give the roots a little room to breath
Or place it on some kind of capillary so it can absorb some of the bottom.

Whats your feed schedual if you wait too long before re watering rw .
If i remember right rockwool gets a lot of aeration by pulling air in with the nutrients thats why most rockwool is topfeed.

Air in your nutrients is always good but i dont think it would help . It might


Are the roots slimey and pop off if you barely touch them?

Ideally you want your roots bone white and sturdy. Fuzzy too but thats a different story

At this point i could only recommend dosing with h202 to kill anything bad and it will add oxygen.
Slip somthing under your blocks like an oven rack.
Then stack the rack on somthing wterproof and non molding fuck 4 leggos will work lol
Stack it up 1/4 to 1/2 high . The roots should air prune themselves but shouldn't rot hopefully

Or buy a bag of hydroton or growstones put it in your tray then set your blocks back on it (basically does the same as i described but also gives a place for roots to grow

Hope it helps i have a hard time articulating whats in my head sometimes lol

Also it looks like you started good had a nice fibrous root system going it just didn't have any where to go to

Do you guys think the plants are worth saving. I’m trying to learn so the expierence is worth it to me but I won’t be using Rockwool again so I don’t want to waste time if I’m not going to get a decent yield. A few of the plants seem nearly dead to me. What do you think? Are the worth trying to save or should I bail and start fresh?

Not so much the rockwools fault

as produce farmers grow crazy huge tomatoes in a small slab of rockwool.

Hard to say bud your first pic looks toasted best to take that one out abd ether chuck it
Or reveg it.

The ones in pic to look savable
Just back off on some nutrients for a few days and rais the light a little so they can try to recover. .

That being said most growers will tell you if you fuck the plant up after 2-3 weeks in flower. Your yeild will be toast.
They might bounce back they might not
But you sure wont yeild as big a crop as you would have.

First thing is figured out how to keep your roots from sogging out.

Its all up to you of course but i would start new seeds now or clones if you got them and try to finnish your grow . This is good experience in bad circumstances

This way you can learn and get some smoke

I agree it’s not the Rockwools fault but it’s my third grow in Rockwool and it just seems too unforgiving for my abilities and ability to stay on top of with my time schedule.

As far as the yield is concerned I’m thinking it’s just not going to be worth it to spend all the time and money nursing them along if the yield/quality is going to be shitty. I’m going to use your advise and the other advise given and see in a week where there at. If it doesn’t look promising I’ll bail and start again.

What medium do you use primarily coldsmoke?

Also if I did revedge them, how does that work? What are the pros and cons of doing it?

Thanks again!

Primarily for the last decade has been in water.

I just tried rockwool for the first time and loving it so far.

Im sold on rockwool for seedlings.
Ive used jiffys and rapid rooters im switching to the rock for seeds.

And im going to pull half setup out to run an experiment with rockwool.

That being said im currently in rdwc.

But have done low pressure aero dwc NFT
Coco and like 2 runs with promix.



As far as revegging you would just put the plant in veg cycle and soon new (mangled ) growth will appear followed by normal growth in a few weeks.

Just an option is all .

If your inclined to bail then bail .

Either way its experience

Ok. For sure the experience is invaluable.

Are there any downsides to revegging?
After a new good veg cycle, would you expect similar results as a normal grow?

Not really some guys reveg on purpose .(i only do it in emergency like when i forgot to clone lol)

Only downside are it might be easyier for it to get problems being an older plant. Not a problem if you got it going good though

I think that sounds like a good option.

Would you expect the yield to be comparable to a grow that went as planned without the problems I ran into?

braves1995 said:

I think that sounds like a good option.

Would you expect the yield to be comparable to a grow that went as planned without the problems I ran into?

Click to expand...

On what the reveged plants or the current?

The current ones are probably not going to yeild the same flower is not the best time for problems. ..

The reveged one can regrow so youll be basically starting over and your new harvest should be like no problems occurred.
For the most part sometimes revegged plants are a little quirky

I was just planning on changing the light schedule and nutes back into veg for the whole tent. If it’s possible the plants will produce a good yield similar to a normally grown plant I think that would be easier than starting over. But if they are going to limp along and not produce quality than I won’t bother. If you think I have a good shot at getting a decent harvest quality AND quantity then I think it would be cool to see the revege process in action. I just don’t want to do it if it won’t be worth it.

braves1995 said:

Here are some pics. I don’t know how to look at the roots In Rockwool. I’ll try to smell them and see on that.

Click to expand...

I would stop watering them for a while (a watering cycle or so) to let the cube dry out a bit. Pick up the plant and you can get an idea as to how much they weigh when wet. Then let them dry out a bit and check the weight of the cube again. Just don't let it dry out completely! Sometimes this can give the plant a fighting chance to beat root rot. It may be advantageous to water less frequently from now on as well. I used to use 4" cubes when I first started to grow. The plants got over 3 feet tall in that little cube it almost looked comical. At that point during flowering I watered 3 times per day but never just before lights out as that is a good way to get the plants sick. I used to water 1. When the lights first turned on, 2. After 4 hours, and 3. another 4 hours after that. I didn't water again until the lights turned back on which was 16 hours after the last watering cycle giving the cubes a chance to drain and dry out a bit in the meantime.