Going to attempt a small semi-self-sustaining tank
So I have no aquarium experience outside of having a few small unfiltered goldfish tanks as a kid. I got it in my head that I'm going to try for a relatively self sustaining tank with a few live plants, 2 or 3 nerite snails, and possibly a dwarf shrimp (no fish). I say relatively because I don't plan on sealing it off or anything, so I can still access the tank should the plants/animals need something, but no filters or pumps or anything else, just the bowl. I'm not sure the exact size of my bowl but I estimate it to be about 1/2-1 gallon. Basically I'm looking for any and all advice/criticisms from those who have experience with these types of setups. I've been doing a lot of research so I think my plan could work in theory, but there isn't a lot out there I could find on a very small, unfiltered set-up specifically. What I have planned:
I'm debating between using EcoComplete or Florite for my substrate. From what I've read EcoComplete seems to be the overall better option but could negatively effect the ph level? Since it's such a small tank I was worried this could effect the animal/plant health...let me know your thoughts. I was also planning on adding a layer of white sand on top of the substrate, 1) for aesthetic reasons and 2) I read it helps keep plants rooted. Let me know if this could be a bad idea however.
For plants, I got a few merimo moss balls and a Alternanthera Reineckii/Telanthera Cardinalis for the bottom of the tank. I want a good amount of plant life in there so I also decided to add duckweed since it won't crowd the bottom of the tank and I think it looks nice. I understand duckweed can get out of control but I don't mind thinning it out whenever needed. I admit I bought the Cardinalis on a total whim without researching while I was browsing my local pet store looking for ideas, because I thought it was pretty lol. After looking into it I'm worried this could be a little too sensitive a plant for this set up, but I have it now so might as well try since I can always replace it with something else later on. I plan on putting the bowl in a west facing window sill that gets full sun from the afternoon until evening, but I have a lot of windows in my house so the room still gets a fair amount of natural sunlight all day. Not sure if that will be enough light for this plant.
My biggest concern are the animals, I'd like to be as ethical as possible so if this set up isn't a good environment please let me know. Again I can't find much on keeping snails/shrimp in really small tanks and most sources reference 5-10 gallons as small lol. I'm not too too worried about the snails, since I gather they aren't picky and thrive in most set-ups. I would -like- to get a shrimp but I'm concerned it would be cruel to keep them in that small a tank, or if they are social and would be unhappy in solitary conditions (Don't want breeding obviously so I would only get 1). The biggest task is making sure I strike a good balance between there being enough animals to produce enough CO2 and waste to feed the plants, but not too much that the plants can't filter out ammonia levels or produce enough oxygen for the animals.
I plan on getting the bowl set up with all the plants first and waiting a few weeks for it to get established and ensure the plants are even doing ok. I'm kinda already decided against getting the shrimp, so I would then just add 2 snails and see how it goes from there, adding another snail or making changes if it's needed until the tank is fully established. I don't mind adding food for the snails every so often and doing occasional water changes, but I'd like to have the tank be mostly self sufficient and not require daily care. I understand and completely expect there to be a lot of trial and error with this project, but I'd like to go into it with the best starting point possible so I thank those of you who read this whole post and are willing to offer advice.