Fungus Gnats: Sand Applied On Top, To Water On Top Or Bottom ?

1,977
263
I saw some tutorials that told me to apply my feeding/watering on bottom of tray ( so I don’t destrub the sand) and a lot of the tutorials did not say anything about feeding on the bottom.
It’s just lifting up trays for every plant and doing that extra work if it wasn’t needed would def be a great thing/less work . But I am def willing if it’s wrong the other way obviously . Well I wanted to see what everyone’s views was? I applied 3 days ago and my population of gnats went crazy down (75+%)

—-
Side note:my battle is BTI in my water once a week, sand on top, yellow traps, wine traps, vineager traps , Azaguard @ foliar

Any other great fungus gnat tips for the battle and advice , keep em comming :)
 
847
143
Increase the dry down times, prune well, clean thoroughly and keep on it, floor fans and good air circulation throughout,yellow stickies and nematodes. The sand is just smothering your roots oxygen exchange likely doing more damage than the gnats. Plus they’ll just go in thru your drainage holes
 
1,977
263
Increase the dry down times, prune well, clean thoroughly and keep on it, floor fans and good air circulation throughout,yellow stickies and nematodes. The sand is just smothering your roots oxygen exchange likely doing more damage than the gnats. Plus they’ll just go in thru your drainage holes
^ well that sucks your saying sand will just do negative to the plant and not be that efficient towards the battle on fungus gnats since they can go through the bottom of the holes, of course there’s always cloth pots ( just sucks when all those gardening websites/YouTube’s were suggesting it)

I got like 300 lb (1 inch for each pot) of sand on my coco and now I’m thinking from that comment I should remove it all .

If anyone has any extra Input or debate with using sand or fungus gnats . I would love to hear it cause that def sucks that so many people think something that is just a negative when they need to be focusing on other ways to defeat them ( if that does not work)
 
1,977
263
I've used sand it was ok. Diatomaceous earth is better, like rolling in glass for bugs :) stick with the bti tho, I use the bti donuts crumbled in the bottom to address drain holes & dress the top for the rest & I haven't had gnats since.
Do you have to re-apply DE every time you water or it gets wet ? If you did , that would be a shit load of work everyday before watering plus dusty lol
 

Jack og

JackOG
Staff member
1,889
263
De breaks the cycle and is beneficial to soil so applied like a dusting a few times won’t hurt a thing and it doesn’t loose its ability wet either . Apply it every 3 days if necessary till those fuckers are gone! But dust it, never more then a flour like coating, don’t dump it in like top dressing. Imagine using a sifter when making pizza dough, that much , and the whole plant can be dusted
 
695
143
Do you have to re-apply DE every time you water or it gets wet ? If you did , that would be a shit load of work everyday before watering plus dusty lol
My theory on it was re apply after watering for a few weeks until I thought the issue was solved. I'm using ss#4 tho, idk if this method would apply to you as I only water once a week so it wasn't really inconvenient.

Another long lost forum member, demontrich, pointed me in the direction of Promis. I used it to handle some root aphids @ an application of 1ml per gallon of water & drenchd those bitches with about 3 gallons for 3 water sessions back to back.

He swore by it for cleaning up fungus gnats in ffof @ that same dose. Its systemic so only use it in early veg, needs like 60 days total to clear out. But again your in coco so idk if the same principles apply.
 
1,977
263
Well I applied azaguard as a drench today ( I see today almost 90% of fliers aren’t even around so i’m At least not losing the battle )

And the question next is should I remove 300 lb (1-2 inches of sand on each pot) and replace with DE air gnatnix ?

My theory on it was re apply after watering for a few weeks until I thought the issue was solved. I'm using ss#4 tho, idk if this method would apply to you as I only water once a week so it wasn't really inconvenient.

Another long lost forum member, demontrich, pointed me in the direction of Promis. I used it to handle some root aphids @ an application of 1ml per gallon of water & drenchd those bitches with about 3 gallons for 3 water sessions back to back.

He swore by it for cleaning up fungus gnats in ffof @ that same dose. Its systemic so only use it in early veg, needs like 60 days total to clear out. But again your in coco so idk if the same principles apply.
When I looked at the npk Promis , it said 21 days (3 weeks) i’m On first week of flower , not worth it or safe to do it on a 9-11 week harvest plants? still sounds like a worthy product for plants and seedlings since I reuse my coco.
 
695
143
Well I applied azaguard as a drench today ( I see today almost 90% of fliers aren’t even around so i’m At least not losing the battle )

And the question next is should I remove 300 lb (1-2 inches of sand on each pot) and replace with DE air gnatnix ?



When I looked at the npk Promis , it said 21 days (3 weeks) i’m On first week of flower , not worth it or safe to do it on a 9-11 week harvest plants? still sounds like a worthy product for plants and seedlings since I reuse my coco.
There ya go azaguard is another good one, id leave the sand mix the de in with it save some time & your back :) lol

Yeah too late for the promis, demon used it @ transplants & up pots to keep any new bugs from having a chance but def not in flower.

I say 60 days because I use it three times in a row @ the 1 ml per gallon dose. He used it stronger before but came to the conclusion 1ml per gallon is strong enough for gnats... I'm not seeing anymore root aphids but I'm still not counting them out.
 
54
18
inch or so of beer in small container will attract and drown a bunch. I read apple cider vinegar with a piece of banana or apple in small bowl or cup works the same . Diamaeous earth which I though was volcanic pumice ? lol - is actually maybe beneficial as a source of silica - stem strengthener ? Also read that it only works DRY (has the bug body destruction property ) idk if thats true...... Also read life cycle is 10 days so I;m guessing 20 days eggs and all . Not a bunch of real experience , reading and listening to bug lady pod cast . Theres no sense skipping anything that contributes to safe elimination . Also read bleaching containers before reuse and discarding contaminated soil - no clue if thats necessary but using a mascara brush to clean bugs from buds ............think the bug lady said that to impress gravity ??? Godd luck - let us know
 
847
143
^ well that sucks your saying sand will just do negative to the plant and not be that efficient towards the battle on fungus gnats since they can go through the bottom of the holes, of course there’s always cloth pots ( just sucks when all those gardening websites/YouTube’s were suggesting it)

I got like 300 lb (1 inch for each pot) of sand on my coco and now I’m thinking from that comment I should remove it all .

If anyone has any extra Input or debate with using sand or fungus gnats . I would love to hear it cause that def sucks that so many people think something that is just a negative when they need to be focusing on other ways to defeat them ( if that does not work)
Idk that’s just me, my opinion. I also found diatomaceous only marginally effective, and only when completely dry too. I had a potato sack sized bag of the same stuff pictured above and an every other day watering schedule so I’d spread it liberally on the top of each 20g on the non water days for a couple weeks, several crops. I’d put a heaping tblsp per pot and distribute it evenly thru the top dry layer and it did help some. But I’ve also watched em traipse thru it all cocky then fly away...Many times. Idk. But if you’re in say coco and you’re watering daily I don’t see much use for de since your medium will always be fairly moist. Not to mention the fact it also just cakes up as a layer on the top of your pot over time doing the same thing as sand like a blanket on a fire smothering oxygen exchange. It gets so bad when you water it takes the water forever to drain thru your top layer of medium. That’s how you k ow it’s smothering them when water flow is restricted ,airflow is massively restricted. Might be fine in grandmas house plants- sand, de - not for me idk . Same thing happens w caps bennies if u don’t let the talc settle out..... But honestly nematodes and a big yellow sticky per plant will go a long way ,reducing to completey eliminating them. With pruning cleaning and airflow dry downs- gone.
 
54
18
sounds like the DE would be better used in a separate container too ,or paperplate ?. I read it's just as harmful to HUMAN LUNGS- use care or a mask ie turn off your fans while you sort it out .

I forgot about the nematodes . She went on and on about the benefits on podcast - getting them directly from the source etc . IDK what a nematode is . Is it like mycorriza ?
 
505
143
Keep a healthy root system and the fungus gnats will be minimal. When I was having root problems it didn’t matter what I hit those gnats with they would come right back.
They can smell a dead/dying root from miles away.
 
440
93
I got rid of them by letting the dirt dry out for a few days and using a half milk half water solution I sprayed the top of the soil with it. Did the trick for me. Didnt cause any mould or fungus problems at all either
 
847
143
sounds like the DE would be better used in a separate container too ,or paperplate ?. I read it's just as harmful to HUMAN LUNGS- use care or a mask ie turn off your fans while you sort it out .

I forgot about the nematodes . She went on and on about the benefits on podcast - getting them directly from the source etc . IDK what a nematode is . Is it like mycorriza ?
Silicosis. Wear a mask w de, for real https://betterplants.basf.us/products/nemasys--beneficial-nematodes.html
 
1,977
263
Well microbe-lift Bmc (Bti) got here in the mail and I will be applying it every 7 days

(Making my final thoughts to remove my sand so I can water on top since coco relies so much on runoff and salt removal , otherwise I would feed through the bottom )
 
I've had good luck using Gnat nix and fabric rhizo pots with a yellow sticky trap
wrapped around the base of plant Gnats can't get out of the bottom of the pot
any that make it through the Gnat nix will go to the sticky trap .
 

Latest Cannabis Seeds

Strawberry Snow Cone

Strawberry Snow Cone

Sour Diesel IBL x Strawberry Cough
12
Regular
New
$100.00
Lemon Snow Cone

Lemon Snow Cone

Super Lemon Haze x Lemon Tree
12
Regular
New
$100.00
Lemon Sherbet

Lemon Sherbet

(Grape Sherbet x Orange Sherbet) x Lemon Tree
12
Regular
New
$100.00
Dreamsicle

Dreamsicle

Sunset Sherbet x Starfighter
12
Regular
New
$100.00
Top