To add to OrganicLawnss comment, Auqaponics (another soil-less) was something I tried two summers back. It is also soil-less and was fun to try it once with the food and fish being something even the kids enjoyed. It can be expensive to start, even with the cheap items. What is your budget? And what do you want to get out of this, just to try it out (taste test) and see if its a hobby or did you want to go larger? My answer to your final question is "YES, you should consider it" but your question is so broad that I am not sure you will get an Answer.

There are grapes to worry about :) and they are just now at full size and going purple too.

I actually have the grape vines surrounded by chicken wire so the birds do not fly in and take all my grapes, still training them to grow up and not out. So an Organic pesticide would be fine for me because the wire also keeps out the half persons too. My naive thought is that organics will soak & absorb into the environment better and not linger around for my kids to ingest like corporate chemicals do. And I have been clipping the destroyed leaves and doing it by hand too. Just wandering if there is a lazy mans solution :)

@ProgrammerGirl just get a PH water test kit, found at pool stores, hardware stores or online. If you test and find the water is acidic then it might be a good thing, plants love acidic water and bugs hate it. on the other hand high Alkaline water is bad, even tap water often has levels of alkaline that plants do not like.

Are you lacking the ground area to plant this tree in your back yard or do you just prefer for it to remain in a miniature state? You could just plant it and then prune it back regularly to the size you prefer. Any plant can be pruned to a preferred size, that is how the practice of Bonsai came about.

Could you possibly do a check of the water and tell us the Acidity or Alkaline levels of this run off water? I would be curious before I made any suggestions.

When I look at a shoot, what am I looking for? size of growth in 24 hours? Diameter? Color?...?

I appreciate that answer, but do you know the scientific name for this species? the bamboo is doing exactly as you are stating here. Though in the Phoenix hot climate (our summers) I am surprised to say it is staying very robust in the extreme heat too (110+ F).

@JMusser my original question was How can you tell if I am overwatering plants. Did you want to put your comment in as a possible scenario to check for a situation like over watering?