Planted Tank Obsessed
Join Date: May 2015
Location: Central Michigan
A 36" stingray sitting on top of a 12g long is a lot of light. I wouldn't necessarily condemn it to low tech/ light setups especially for nano sized tanks. On a 55g, it would be a great low tech light and you would probably need 2 for most plants if you aren't injecting co2. A 36" 24/7+ would also be a tremendous amount of light without co2 but as previously mentioned you can adjust the intensity to suit whatever you're doing but it's more controllable, which I like (I own both models).
If I were to do a 12g and I was debating between the stingray and the 24/7+, my first question would be budget. If I was trying to go "cheap" (in price, not quality) I would buy the stingray. If budget wasn't really a concern, I'd for sure get the 24/7+ dim it to about 60% and suspend it (or find/build some risers) atleast 7-8 inches from the surface, especially without co2 injection. I'd raise the stingray up atleast 4 inches also.
Canisters are nice, I like them. You can put whatever you want in them and for a nano, IME, the more filter space you can play around with, the better. You can run strictly mechanical, biological, or chemical filter media or run all three which most of us do. The issue I see is creating equal flow through out a tank that shallow and long. I've never setup a tank of those dimensions so that I'll leave that to someone else but if current isn't reaching to the other end of the tank you have quite a few options out there to increase flow. One I suggest for low tech no co2 tanks is constant surface gas exchange, I use an azoo palm filter with floss in it so it overflows and breaks the surface, creates a few short-lived large bubbles and a nice ripple for my 30cm cube (which I have 2 12" stingrays 7-8 inches above the surface) but I would love to put a little Ehiem with pipes on it.
You can go a long time (3-4 months) without cleaning them and they will still produce water flow but will also be producing other we don't want but since you want to have a good maintenance schedule anyways, I would shoot for atleast once a month. It's not hard and if you can open a cookie jar you can maintain a canister filter. Aquasoil may also stain your sponges brown if you don't keep up on your initial daily water changes. Ask me how I know lol.
Canisters can also be hidden out of sight very well and with glass or acrylic pipes, you will hardly even tell you have filter equipment. Consider an inline heater if you get a canister too. Not a lot of room in a 12L for most heaters. With an inline heater, glass/acrylic pipes, and raised light fixture, all you will see is your tank and almost zero equipment.
The amazonia is all you need like previously mentioned. I'd use the AS powder type though instead of normal. It will make your substrate look mor uniform and to scale.
For a low tech/light tank, if you can manage to not have too much light, Seachem Excel works very well for a carbon source.