[DocTim420]

A post I made in different thread--this might help (think Amazon?).

Originally Posted by DocTim420

As we all know, Bacillus thuringiensis serotype israelensis (BTi) is effective natural pesticide to control Fungus Gnats. So how do we measure BTi? Which product is the best "deal" for buying BTi?

Well, that question requires a little back of the envelope math before one can actually compare different BTi products. You see, BTi is measured in International Toxic Units (ITU) at various concentrations ranging between 100 to 7,000 ITU/mg. The "Active Ingredient Percentage" on the label is just part of the story...gotta include the amount of ITU/mg.

An 8% "active ingredient" product formulated with 1200 ITU/mg has 96 ITU (1200 x 0.08) for each milligram of product.

A 3% "active ingredient" product formulated with 7000 ITU/mg has 210 ITU (7000 x 0.03) for each milligram of product.

Hmmm, that means the 3% products has nearly twice the amount of ITU than the 8% product. WTF?

Also, application methods are different. Some products are RTU (ready to use) for both soil and water applications, others like Vectobac require the preparation of fermentation slurry to activate the BTi, and some are only water soluble (not to be mixed directly with the grow medium).

Since not all BTi products are "equal", I have prepared a comparison of the "usual suspects" and correlated everything to cents per million ITU.



Gnatrol is the most affordable, but can only be used in a liquid suspension form--you can not add the powder directly to the grow medium.

Bits is the 2nd most affordable and can be added to both water and the directly to the potting soil. When added to the water, BTi is instantly activated...but when mixed with potting soil, BTi is gradually activated (time release of sorts) for about 21 days. Bits are basically corn cob bits sprayed with BTi.

Dunks are slow acting (gradual release as the "donut" dissolves) and can be added to the potting soil directly--but must be crumbled to a powder like consistency (PIA). Dunks are pressed donuts made of gypsum and cork bits sprayed with BTi.

I have no experience with Vectobac products but a special fermentation slurry must be prepared before the BTi is activated (an additional step that most BTi products do not require).

Microbelift BMC is already in liquid form and like Gnatrol, it must be diluted in water before use...and from my analysis, is not a bargain.

I previously used both Gnatrol and Dunks, but for the past few years I exclusively use Bits for my source of BTi ($120 for 5 gallon bucket). I mix Bits directly to my water (30 ml/20 gallon rez), mix Bits directly in the potting soil (5 ml/5 gallon container) and mix Bits with my top dressing fertility (7.5 ml/5 gallon container).

One product for all. Admittedly, I could use Dunks form my water rez, but since that rez is used and refilled daily, I prefer the faster acting Bits over the slow release Dunks.

So there you have it. If there are other BTi products you want included in my analysis, please let me know and I will be more than happy to add them.

[LBones]

Hey ganjygav, does the damage look similar to this by any chance?

I've had significant fngus gnat problems in the past. Similar to what someone else posted on here, I let the soil get a bit more dry between waterings, cover the top 2-3inches of soil with perlite, and lots of sticky traps. This works for me without fail and usually takes less than a week to get rid of them.

[LBones]

Whoops, meant to post link https://www.icmag.com/ic/showthread.php?t=343000&page=2

[knuckles]

The ONLY thing that that has ever worked for me,on a consistent basis are nematodes used two weeks apart ongoing.

[philberg]

Mosquito dunks will rid the grow of fungus gnats. Just crumble one up and sprinkle it on the top of the medium and say good bye to gnats for good. Just a small pinch of dunk will get the job done in about 3 weeks.

[JAWS]

ENOUGH

PLEASE listen to me on this issue.

get $25.00 go to home depot and buy this PRODUCT.



get the granulars not the LIQUID.

spread out a THIN layer over your soil then either water or wet it down with a spray bottle.

you "WILL SEE" results by the next day, by weeks end your GNAT problem is no longer a problem and never will be again as long as you have this product in house..

like anything when you bring new soil in it will also need treated..
do not touch with your hands, just sprinkle with a spoon and throw it away.

if you have GNAT and you do not go get this PRODUCT then enjoy your GNATS..




do it

[DocTim420]

Originally Posted by JAWS

ENOUGH

PLEASE listen to me on this issue.

get $25.00 go to home depot and buy this PRODUCT.

View Image

get the granulars not the LIQUID.

spread out a THIN layer over your soil then either water or wet it down with a spray bottle.

you "WILL SEE" results by the next day, by weeks end your GNAT problem is no longer a problem and never will be again as long as you have this product in house..

like anything when you bring new soil in it will also need treated..
do not touch with your hands, just sprinkle with a spoon and throw it away.

if you have GNAT and you do not go get this PRODUCT then enjoy your GNATS..




do it

NO!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Investigate the active ingredient's half-life. Your "jaw" will drop to the floor...especially the half-life for organic soil.

[troutman]

A dilute solution of hydrogen peroxide will kill them.

What you need is a 0.6% solution. Don't use a stronger solution.

Mix 1 part of 3% hydrogen peroxide with 4 parts of water by volume to get 0.6%.

Soak the soil and bye bye fungus gnat larvae.

Note: Leaving the top of you soil dry out a little will discourages fungus gnats. Constant moist soils are what they like.

[DocTim420]

Yep...H2O2 will work, but it will also annihilate the microherd too. For organic soil based grow mediums, a thriving microherd is almost required. But H2O2 will do the job as well as detox the grow medium.

[troutman]

Originally Posted by DocTim420

Yep...H2O2 will work, but it will also annihilate the microherd too. For organic soil based grow mediums, a thriving microherd is almost required. But H2O2 will do the job as well as detox the grow medium.

Some soil could be kept in a separate container with a screen that doesn't allow fungus gnats to leave or enter.

This soil once free of fungus gnats could be used to inoculate the pots again.