Could Fungus Gnats kill a plant?

I've got a bunch of plants that are receiving the best treatment possible. I went over it in another thread.

But they're still dying.

And they're dying, seemingly because they refuse to drink water. As if the pH is 2 or 13.

Could it be possible that I have such a bad fungus gnat problems under the surface that the roots (even though they look healthy to me) are done for?

And if so, what else can I do? I've been using Mosquito Dunks for months now and I thought they were all dead.. the yellow sticky traps are basically clean.

It seems like if this is the case, then the plant is simply not able to recover and form new roots, even in brand new soil..

What do I have to do to fully diagnose these plants? Yank them out of the ground and look for what?

Hi Chen, I still say your pH is off
Those gnats like moisture (and root rot, gawd, hope it's not pythium?)
you already think they're dying (they're not, they're on strike, something ain't right) so why not let them get good and thirsty now, dry out the surface good,
stir surface daily to kill eggs
I take that panda paper and cut circles to cover my pots. white side up

But I've watered with every possible pH, most notably with just regular tap water that has a verified pH of ~7.

And if you agree it's the fungus gnats, why would it be a pH issue?

are u reusing soil?? what type of pots u using? are the pots new?? have they be cleaned well if reused?? yellow pics suggest they are either not being fed or are unable to feed. which in turn suggests either your ph is way off or your roots are having a repeated issue where they cannot feed. just my thoughts. guys and gals have much more experence here than i.

Could it be that the mosquito dunks you have been using for months is affecting the plants adversely? If the yellow sticky traps are clean, why are you still mosquito dunk? Treating a plant with pesticides when you he not problems could be affecting the plant.

mosquito dunks !?!!? wow, eagle-eyed THC, I missed that.
Jesus, Chen, how big are your gnats?
Don't do that, yuck, I'd rather smoke gnats.
Do you mist your plants? Good time to start, wash that crap off.

Chen said:

But I've watered with every possible pH, most notably with just regular tap water that has a verified pH of ~7.

And if you agree it's the fungus gnats, why would it be a pH issue?

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7.0 is high, 6.5 tops
I don't agree it's the gnats but they are an irritant. Do you see eaten leaves? I don't think the things eat enough to cause damage.
Like THG said, you may have done more harm going after them with those dunks.

what are dunks??? i had a bout with the gnats last year when i ran dirt grow. a layer of sand on top fixed it. i never really had an issue with the gnats, just an aggravation.

grass hopper said:

are u reusing soil?? what type of pots u using? are the pots new?? have they be cleaned well if reused?? yellow pics suggest they are either not being fed or are unable to feed. which in turn suggests either your ph is way off or your roots are having a repeated issue where they cannot feed. just my thoughts. guys and gals have much more experence here than i.

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Yes, soil.

New pots.

Yeah, that's exactly my thought as well. Everyone was telling me it was a pH issue but I'm starting to see that's a root issue.

Question is how do I fix it?

The Hemp Goddess said:

Could it be that the mosquito dunks you have been using for months is affecting the plants adversely? If the yellow sticky traps are clean, why are you still mosquito dunk? Treating a plant with pesticides when you he not problems could be affecting the plant.

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Because I stopped using them for a week and the gnats came back.

The plants weren't growing beforehand either, hence the dunks.

Is it possible the dunks have done so much damage that the plants cannot replenish the roots?

If so, how do so many people use them?

sopappy said:

Jesus, Chen, how big are your gnats?
Don't do that, yuck, I'd rather smoke gnats.
Do you mist your plants? Good time to start, wash that crap off.
7.0 is high, 6.5 tops
I don't agree it's the gnats but they are an irritant. Do you see eaten leaves? I don't think the things eat enough to cause damage.
Like THG said, you may have done more harm going after them with those dunks.

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I'm starting to not like you, pappy. This is a serious issue and your questions are just moronic. Straighten up. And don't get butthurt because I told you to.

Fungus Gnats are tiny.

Fungus Gnats aren't something you can ignore and just smoke. You're thinking of white flies.

You don't spray Mosquito Dunks, you add them to the water.

pH 7 has been absolutely fine for years.

Fungus Gnats don't eat leaves. They eat roots

I mean, it's possible that the dunks have made it even worse, but they've also made it better (essentially) since there are no gnats..

It's just a clusterfuck.

yarddog said:

what are dunks??? i had a bout with the gnats last year when i ran dirt grow. a layer of sand on top fixed it. i never really had an issue with the gnats, just an aggravation.

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I put a layer of sand on top of the soil and when I watered it, it just ends up mixing with the soil.

No idea what the logic is there. Just another mystery.


EDIT: Just thought of this..

If the plants aren't taking up nutes.. wouldn't they also be wilting because they couldn't intake water either? Because they're not wilting.

So, they're taking up water but no nutes?

Damn, sounds like a pH issue again, but it can't be.. I've tested it with every pH meter I can, including those stupid litmus papers.

It's like someone has been mixing lemon juice into my water supply..

Should I go put on my tinfoil hat and buy some distilled water from the gas station?

I had a bout with gnats last crop.

I tried Diatomaceous Earth and it was a PITA to deal with. If you try it, make sure you turn your fans off before you open the bag. I learned that lesson. LOL And, wear a mask.

I also used the mosquito dunks (chucks). The way I did mine was to put a pan of water in the room and placed the dunks in that. It did attract some gnats to it but they were also, pretty much a failure.

In the end, I did what always seems to work for most.... let the soil dry out. The gnats die. The eggs don't but just keep your soil on the dry side, rather than the wet side. Especially, the first few inches from the top. I watered just enough to soak the roots. Rather than water until it flows out the bottom of the pot. The roots absorbed the water and the surrounding dirt dried out pretty fast.

I filled a handful of sticky yellow cards with gnats before mine finally resolved but eventually I did win.

I didn't yank any plants to check the root damage but when I harvested I didn't notice the root balls being and smaller or different than normal.

Yellow stickies and dry soil. That's what finally worked for me.

I am sorry, Chen. I'm not laughing at you, I was just trying to lighten things up, probably the wrong approach but you're getting lots of help now. I hope it turns around in there.

chen, pappy always tries to find a little humor. he has lightened my mornings plenty. i do enjoy his outlook!... they sell what looks like glass beads that does the same idea as sand but costs a little more.(grow store). this wont mix with your soil. did u say u reuse your soil???

grass hopper said:

chen, pappy always tries to find a little humor. he has lightened my mornings plenty. i do enjoy his outlook!... they sell what looks like glass beads that does the same idea as sand but costs a little more.(grow store). this wont mix with your soil. did u say u reuse your soil???

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well, the chap's having a rough go of it and I crack wise, inappropriate
but I appreciate the sentiment, thanks.