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SM-90 How good is it?

Discussion in 'Marijuana Plant Problems' started by Magnetar, Nov 27, 2009.


    Magnetar Active Member

    I have heard that SM-90 works good for killing bugs.

    But what about white flies?

    These microscopic fuckers are hard to kill.
    pot smoker

    pot smoker Member

    dont do it, put a fan on low and put it about 2 feet away from the plants, the plants will get bigger from all the fresh air, and the bugs cant stand wind, thell be gone withen a week, if its ousde, spray a 18inch ring of sm90 around the plant(dont get it on theplant it will die)

    Abnjm Well-Known Member

    I mix 3ml / gallon into every nute change. I also use a 5 : 1 mixture of water and SM-90 as a foliar spray about once a week. I think the Sulphonated Canola Oil helps keep the critters down, and slows fungal growth.

    This is my first grow using the stuff, and I have not had any fungus gnats colonizing my grow. In addition, it smell really nice. :bigjoint:

    I did have one issue with the stuff during my 3rd mix. I decided to add H2O2 to the mix with the SM-90. The next day I had a sludge pond:


    Remixed the next day without the H2O2, and the reservoir was clear.

    Magnetar Active Member

    I put 2ml per gallon in my res and it raised my ph from 5.5 to 7.5 and now I can't get it to stay down below 6.0 even after changing out the nutes twice. It did smell like citrus and totally removed the skunk smell. First time my grow room has not smelt like a skunk just farted since forever.

    Sprayed the tops once with SM-90 and it took out 99% of the bugs.
    Guess I need to keep spraying every week now?

    Abnjm Well-Known Member

    I didn't realize it spiked the pH, but I've used it from the very first mix for this grow so I wouldn't have a comparison value. I will check pH after blending just the SM-90 next time. I haven't sprayed the plants in the flower chamber since I went to 12 / 12 lighting, but I hit the clones once a week.

    Good luck with your grow!
    skoobie dew

    skoobie dew Well-Known Member


    I just made a quart of ro water and added about a teaspoon of sm-90. It took the ph from 7.5 to 8.4. Then I added 3 drops of advanced ph down and the ph came out at 5.4.

    It should be easy to knock your ph down with either plant p.h. down or epson salts.

    Magnetar Active Member

    Yeah, it goes down right away, but then it creeps back up to 6.6 if you don't keep adding ph down to the reservoir all the time. I never had this problem before I used SM-90.

    Does anyone know how SM-90 kills bugs?

    Is SM-90 systemic to sap sucking insects when used in your reservoirs?

    Can you use SM-90 in soil nutes?
    skoobie dew

    skoobie dew Well-Known Member

    Sm-90 suffocates insects. I don't think it will do anything to sap sucking insects when used in your res. It is essentially a kind of liquid dish soap. The reason to use sm90 in your res is to keep mold away & help with nute uptake/use less nutes.

    Magnetar Active Member

    SM-90 did not kill them, had to use Spinosad, that nuked them.
    And they were Western Flower Thrips.
    I hope they don't come back.

    micromacman Member

    sm 90 through the calibration on my ph meter off.

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