I'll have to take a pic of the 1.5 cubes, beside a ruler(if i can find one LOL) i know what your saying, going commercial is different then being a hobby.
As a past business owner, owned a pool hall for many year's. You can't price items like a hobby person does. You have to call the companies and say hey, i'm looking to go commercial what kind of deal will i get if i buy direct. Cause in that sense your going to be buying more then just a case or 2 of there item.
And i totally agree with you on getting more bang for the buck and finding the cheapest route to anything. It allow's you 1 of 2 things. To cut cost so you can compete,least till word of mouth on how great your product is compared to store XXX. And it helps your profit margin, and we all love a higher profit to cost.
On that note, like i've said you take someone like me who's as green as it can be to the hydroponic thing. I loved the STG, seem's to work well. Didn't add anything to my water, and lord know's i had a hell of a time with my water. In the long run, when i get waaay more then just a dozen tomato plant's going will i be doing STG, heck i dont even know if i'll keep them in Bato bucket's but we'll see
PS: we're about to buy a new camcorder so when i get that if there is anything you'd like me to show you or have ?'s about the STG i'll be able to show you more.