Flood & Drain with Gnatrol

Hi guys, wondering if someone can clear something up for me please...

I am running a flood & drain setup with 4 plants vegging under a fluro atm (day 20). A few days ago I came home and noticed a smell coming from the setup. It was sorta like a pond smell, a watery smell. I looked at the setup and everything seemed ok, but when I put my nose close to the res, it absolutely stunk. I also noticed these little flies appearing on the same day, and after some investigation, Im pretty sure they are fungas gnats. I cleaned everything on the weekend, with disinfectant, but this has done nothing. After spending hours reading different sites, I have found a product called Gnatrol. I want to use this to kill the babies feeding on the roots, but Im confused as to how it should be applied. They say 1-8 pints per gallon, or 3-24 tablespoons per gallon. My res is 42 litres (11.1 gallons). Should this just be added to the res next time I clean everything out? And how much should I buy? Isnt 8 pints a gallon? (Im lost with pints and gallons).

Sounded Bad , Trounce Or A Miled Dish Soap Should Work On Pests

Yes 8 pints is a gallon.

FUCK gnatrol!

I had a problem with fungus gnats for 2 months trying to use that crap.
Then I tried "gonats" and they were gone in 3 days.
It was easier and it's far less toxic to us and the plants.

Thanks guys, but since then, I couldnt find Gnatrol anywhere, all I could find was Gnat Off, I used this and it got rid of them all.

I have read that H202 or Hydrogel prevents it from the start.

Preventing it from the beginning is even better. Nice find.

oops its not hydrogel, its called Hydro-Guard

I'm not so sure H202 has any direct effect on fungus gnats, but it sure will kill any fungus or other pathogens in your reservoir. If the fungus is a food source for the gnats, H2O2 should remove that source.

I treat my tanks about every 3-4 days with 50% H2O2 @ 1ml/litre tank volume. I use yellow sticky card flytraps placed on the surface of my rockwool growing media to catch the adults.

I still get some gnats, but I don't get tons of them stuck to the traps. I've seen really bad infestations- and my problems are fairly minimal. The few gnats I do get don't seem to have any effect on either my mums nor the flowering plants.

However, the gnats are more attracted to my mother plants (which run under 24hr light) than they are to the flowering plants.

In case it happens again, you might try, assuming a grow closet, is to get some co2, or even some dryice, and fill the closet with co2, it'll kill everything but your plants. In fact they'll love you for it. It's reasonably priced. You should be able to get a 50lb block of dry ice for under $20.00
Peace