[OrionGirl]

Depends on the veggie. I've left zucchini in a tank for three days or more, and never seen a spike--but that was in a very established tank, with lots of plants. The firmer the veggie, the longer it can soak--carrots, for example, are good for a long time.

Lots of people worry about they fish not eating. Here's the thing--if you are offering foods appropriate for the fish, in sizes appropriate for the fish (which you are), and the fish doesn't have a sunken belly, it's probably eating just fine. There are definite symptoms of a fish that isn't eating, but since you are seeing him eating the algae sticks, and you know he's on the wood, I wouldn't worry.