HELP! COCO root rot symptoms?

[rangerjake]

Growing in Coco/perlite mix. About 60/40 C:P.

Tent is 2x 315LEC. Constant 73-77f. Constant 46-52% humidity. 24/0 cycle. Fan circulating air in the tent. But no exhaust fan (when I run the exhaust it drops the temp in the tent to about 69-70 due to cooler space).

Been feeding GH series (ArmorSi, Cal/mg, micro/gro/bloom, nectar, rapid start) at about 800ppm/5.9-6.3ph over the past 10 days. Keeping the nutes light until I get a better handle on what's going on. Of note: most of these nutes are leftovers from about 18 months ago. Been stored in cool/dark places, etc. I also have once, and will again, alternate in Micro hardwater for regular micro due to needing to supplement some harder water into my watering.

Plants are about 3 weeks since they germinated, maybe a few days more.

All are growing, some slowly. But there are some diverse unique symptoms that, when taken together, appears to indicate root problems. But that's the question.

Two plants #1 and #4 (both Nirvana Somango XXL) have upward clawing leaves on some of the older growth. The coloring is darker, but looks normal. One of the Somango plants, #5, looks excellent with not a lot of issues.

Two other plants, #2 and #3 (both Critical CBD) are on the lighter color side, one #2 with yellowing in the newer growth. The other of the two plants #3 about 2 weeks ago after transplant developed some yellow/browning inbetween the veins on what is now the oldest leaves (single and 3 finger leaves). It has generally not spread up to newer growth.

Additionally, after both feeding and plain waterings, and for a solid 24-36 hours after, the surface of the coco gets an almost greenish algaeish film. It doesn't go below the very surface millimeter. Sometimes I just hand aerate the surface coco to let more air in/provide more surface area.

A few days ago I cut holes in the bottom of the fabric pots, which has helped drainage.

The past 4 watering/feedings have been done with Hydroguard.

Would be good to hear people's thoughts.

[rangerjake]

This is the algae on the coco surface. Appears after watering, diminishes as the surface dries out, reappears after watering. Same cycle for a couple weeks now. This has gotta be the source of the struggles for these plants. These photos are 24 hours after last water. Typically 36-48 hrs between water/feedings.

Thoughts/ideas aside from letting it dry out for eliminating this?

[gbauto]

Is there any air exchange in the tent?
Without some exchange, your plants will consume all of the co2 in the tent and 'suffocate'.
Coco is a hydro system-it's impossible to 'over-water' coco.
I run 3-gal fabric bags running coco/perlite in a dtw tray in my 4x4 pheno tent.
I will hand feed them once daily to run-off. This will usually result in the top of the media getting dry, but the bag is still moist.

https://photos.app.goo.gl/qaMoWgxHHAhN6Kvr7

[gbauto]

Re-reading your post.
The nutes should be okay as long as nothing has precipitated out of solution in the bottles.

[rangerjake]

Is there any air exchange in the tent?
Without some exchange, your plants will consume all of the co2 in the tent and 'suffocate'.
Coco is a hydro system-it's impossible to 'over-water' coco.
I run 3-gal fabric bags running coco/perlite in a dtw tray in my 4x4 pheno tent.
I will hand feed them once daily to run-off. This will usually result in the top of the media getting dry, but the bag is still moist.
https://photos.app.goo.gl/qaMoWgxHHAhN6Kvr7

This is an interesting thought. And makes some sense. I run fans in the tent, and there are vents in the tent, but because the space is about 55f and the LECs don't give off a ton of heat, the mid 70s temp has come with no exhaust fan. When I run the exhaust fan on the lowest setting it drops the in-tent temp to around 68-70. I'll run the exhaust for a few days and see what happens with cooler temps. I really focused on warmer temps as the seedlings were taking hold. But now that these plants are established they can probably handle upper 60s.

Will report back.

Holler with any other ideas fam.

[gbauto]

Yep, you need to warm your lung room to around 10-15 degreesF lower than your target temp in the tent.
No air exchange will strangle plants, so that HAS to be corrected.

[CaptainWiese91]

Depends on how big the tent it.
I have no exhaust at all in my tent. And in the 12 hours of darkness the tent is 100 % closed. And I have no problem at all. And my plants are way bigger than in this post. So I don’t think it’s the problem.

[rangerjake]

Yep, you need to warm your lung room to around 10-15 degreesF lower than your target temp in the tent.
No air exchange will strangle plants, so that HAS to be corrected.

The tent is 5x5. The lung room will not be any better than about 20 deg below target temp- no changing that. My hope is that I can add in more exhaust fan ventilation (although it was hardly a sealed environment before- but understandable how there wasn't enough active energy to draw new air in) and do it in phases of the day akin to day-night outdoor differentials and have much of the day 74f/50rh, and then fan on down to 66-68f/38-40rh.

We'll see how that goes. But if other's think the plant symptoms are "rooted" somewhere else, chime in. Want to spend these next couple weeks straightening out this issue so I get a few weeks of healthy veg before the flip.

Thanks!

[rangerjake]

Bump to the top. Def soliciting thoughts and ideas.