Small white and green bugs have attacked my lettuce

They can come in through a window.

They can come in on your clothing.

They can come in on your pet.

I was thrilled for the first few months of growing stuff in my aerogardens.  I never grew stuff outside cause I always hated bugs. I thought that I wouldn't get bugs with indoor gardening.

Bottom line is you will still get bugs.  Less often and more easily dealt with as opposed to outside but you will still get bugs.

HOWEVER, One of my greatest thrills is to see the groundhog that lives next door staring at my peppers through the window!

Indoor gardening does solve the problem of ground hogs, rabbits, and deer.

I use two different products for bugs.  I had thrips not aphids but both products work on aphids too.

Both products are fairly expensive.

The first product is called SNS 209.

It is a rosemary extract.  Bugs hate rosemary and this systemic additive makes your plants taste like rosemary to the bugs and they won't eat it.  Won't kill the bugs. They just leave cause they don't like the taste of what your are serving.  I use this as a preventative and periodically add it to the bowl. You can also spray it on the leaves.

The other product is called Azasol. 

They recently figured out how to make the active ingredient in neem oil to be water soluble. This comes as a vary light and fine powder. Be careful you don't breathe it.  I put 1/2 tsp in the bowl WHEN I HAVE DISCOVERED THAT I DO INDEED HAVE AN INFESTATION.  It's a bit too expensive to use as a preventative.  It is also a systemic and kills the bugs when they eat it.  At almost $50 for .75 oz, I thought it was really expensive but the 3/4 oz. actually goes a long way cause the powder is so lightweight.

Both products are considered insecticides but can be used up to a day or two before harvesting.