Fantastic question, first off I would be making way too many greenhouses for people, an enormous amount of them, do you think they will let me choose the volume of the fish tanks because commercially you can as a private consumer get 15,000gallon/57,000liter tanks made to order, and you can get 5000 gallon/19000liter ones off the shelf.
If they're willing to give me 5000gal tanks on a monthly basis, I want 5 a month.
First we contact a glass recycling facility with implosion capabilities for sand remanufacture. We find out what their minimum accepted donation is if they get to keep the sand at the end. This is our disposal stream for any excesses we may run into over time.
Then, starting in your hometown (since this is presumably where the shipments are delivered, and um, sorry about your driveway for possibly 2-3 days a month).
The first month is the worst one because we have no viable beginning income stream with which to buy the appropriate tools, so we'll have to dismantle the wretched things by hand. We will break at least one, this is not intentional but we must accept this cost.
We will also keep one tank whole, for us.
Then, we begin initial sales.
It's basically trivial to sell large panels of glass for like 200 bucks each if you go to any bougie farmer's market. You aim at the nearest middle class individual who looks like they need a hobby, and offer to install a raised bed with a greenhouse lid. Either they'll buy your services, or just the lid for the existing garden bed. This is because once you have any kind of leisure and land, you will become a garden enjoyer. You may not be a gardening enjoyer, but you will be a garden enjoyer. Thus, the offer of a huge panel of high quality glass for <one afternoon's wages if even that> is unbearably tempting. To put such inconceivable luxury in perspective, it's like drugs for a person currently being denied goddamn medication by goddamn insurance. Simply an unavoidable temptation bordering on necessity. They must have it.
Now, having gotten some investment funds, we can buy tools for disassembling the tanks way better next time. We'll repeat this cycle a bit, until we exhaust the local supply of bougie types. Tools galore!
But first let's revisit our special tank we kept whole!
That one is going to be my your little greenhouse!!!!!!
I will cut a little door and a little window for an exhaust fan, and then probably need to frame those so they don't crack but that's pretty trivial too, and then bam, greenhouse. Made of actual glass, it will if positioned properly be good through the cold season in almost all latitudes and altitudes.
Okay shit wait I have to go to dinner fuck
instant bus shelters for every bench and park in your town whether the dipshit city council likes it or not; yes it's breakable but it's also useable and more importantly it's enjoyable while used meaning the city now has to take away a liked thing instead of coasting on absence
contact local homeless shelters and camps and ask where else they want em also
ask local museums and rec centers also they know this stuff
decorative functions in the home (eg: bedboards door art wall art table covers counter tops when properly backed and reinforced because large aquariums are and i cannot emphasize this enough SUCH high quality fucking glass actually plausibly you could use these for doors entirely and i don't mean sliding style though that too obviously)
contact local food banks and ask them to let the local garden growers know that there are free greenhouse kits and panels for pickup (ps donate your excess squashes to the local food bank)
fun fact you can also just use them as aquariums or ponds or also pools if you have that kinda space and shit
funner fact they're food safe grade so the fish don't die horribly which means you can also use them to make raised beds or whatsitcalled aquacultures i think
