Safe insecticide for my biofilter?

[Ian Cameron]

I have 2 45gal tubs with hydroton and the little critters in the in-gound green house just love it. I am wondering if a strong garlic spray will harm my fish / bacteria? This is a well established setup, and lady bugs are not available to me up here. Any ideas?

[Luke Smith]

Are the little critters doing something bad? Maybe they are even good to have. We can't tell until they are known.