light proof my pots

I have some seedlings about a week into the grow. they're quickly coming up on 2 inches, and I'm sure are starting to grow nice roots. the pots I'm using are just gallon milk jugs cut in half. I thought it would be a good size for some small plants, and it's free. so now, before the plants get rooted in the hydro media and can't be moved, how can I make the pots light proof? I thought of black paint, but I don't want any chemicals from the paint getting into the water. maybe line the pots with black plastic, but that might not block enough light. what can I do?

tin foil works for me.


VIVA LA GANJA

sticky black tape, i use clear pots and have been told i shouldnt but never does n e harm to my plants.

I found the perfect solution to my problem. I tried tin foil, which worked well keeping out light, but I'll be moving the plants to ebb and flow once they are big enough. I started to really worry about having the metal foil in the water. landscaping fabric! the stuff people use to try keeping weads out of flower beds. it's like a plastic fabric. it blocks out light, but still breathes and lets water pass. I lined by pots with that and used a bit of masking tape at the top to hold it in place. perfect.