Updated FTS Feb 2020
Build idea and tank/equipment
So I wanted a desktop planted tank for my office, and I found this 3.5g Top Fin Enchant Aquarium for ~$20 at Petsmart. I already had a cheap amazon clip-on LED light (~$10), and a 50w aqueon heater from another tank (I got this used, but new it would be about $15). I also had a digital timer to control the lights, but it's not really needed so I won't include that in the build cost.
I had some extra plants I got from when I was setting up the 55g, and from another 10g tank I was breaking down, so those went in with some rocks from the yard. I also already have a healthy breeding colony of Red Cherry Shrimp (and of course I ended up having some pond snails tag along on the plants - some of the purple shelled, purple footed ones are nice to look at, and the have interesting antics nice for a small tank).
So total actual out of pocked cost was only for the new tank ($20), but if you include everything but the flora/fauna/light timer, then it came out to ~$45. I think it has come out fairly nice! It's very low maintenance, I top of with water 2x a week and do a small water change maybe once a month. The office mates think it's fun to watch and they amuse themselves by worrying about a snail breakout (they don't make it due to the lip around the edge of the tank, but not for lack of trying).
I removed the stock hood/light the tank comes with, so it's open top. Unfortunately the filter isn't covered, since the top covers it originally. I made a 1/4" plywood top to cover, but even with the inside painted I haven't figured out a way to keep it from growing mold on the inside. I may try to cut a piece of plastic out and glue it underneath at some point. I added a large piece of filter sponge over the stock filter intake to keep shrimp from getting in.
Here is the initial attempt at the hardscape layout:
First FTS Nov 2019
[I set it up in Sept, but apparently forgot to get any photos except of the hardscape!]
Nice closeup of some Buce
From the front