I'm leaving for college this week, and like many other college bound kids, I'm considering getting some fish. My dorm rules say that a 5 gallon tank is the max size. I'm looking into getting a 3-5 gallon tank - but I've heard and read so many different and contradicting stories on what you can keep in these. Most people recommend bettas and leave it at that - and I'm considering it, but I really want to hear about any other options I may have. A few threads said dwarf puffers could live in a five gallon tank, and they're pretty freakin' adorable in my opinion. Would this and maybe a snail work? What type of snail if yes? Lastly, I'd love to get some recommendations on what tank to get plus filters, pumps and etc. I'm fully willing to research and take care of any fish that might require a little extra care than normal: I want my fish(ies) to be happy and healthy! Thanks in advance!
Dwarf puffers need at least 5 gallons of space for one, roughly 5 gallons for each additional puffer. 5 gallons is very small compaired to the general scale of fish tanks, but it is large enough to go through a nitrogen cycle. This will be your main focus, while you cycle your tank, you can think of stocking ideas, although they are limited with a tank that small. Honestly, the nitrogen cycle is a very simple concept of kick starting bacteria like ammonia and nitrites, then reducing them to an invisible reading, while raising necessary bacteria (nitrate) which NEEDS a reading in order for your tank to be cycled. It goes in the order of ammonia (rises, then becomes invisible) then nitrite (rises, then becomes invisible) and nitrate (rises and should stay at a rate of under 25)
To start the nitrogen cycle, you need an ammonia source, and nature will take it from there. Using fish is considered `inhumane` unless you use hardy fish that are capable of surviving a nitrogen cycle. For a tank as small as 5 gallons though, it would just be easier to go fishless, and use a different ammonia source. The most simple is just using fish food. This will result to ammonia, then the ammonia will die, and continue into the cycle. You can read plenty of articles and posts on how to do it as well as specifications and details.
Now to stocking. 5 gallons is too small for almost any fish besides dwarf puffers and betta splendens. Know that if you have one dwarf puffer, you cannot get anything else. They are very territorial and because of their small size, your tank will look rather empty. Dwarf puffers are also sensitive to water quality and are probably intermediate level so if you have no experience with fish, I advise against it.
I myself am only 14 but I am telling you this out of experience and research, and I can say for SURE that 5 gallons is the smallest tank size for a well suited community tank. The ideal and most proper community tank set up is probably having 1 betta, 2-4 ghost shrimp, and a small mystery snail of some sort.
Other small fish like neon tetras and danios that could seemingly fit in a 5 gallon tank would actually grow much too active and probably need 10-20 gallons of space.
Remember that your water quality must be good and better than mediocre, if mediocre consists of ammonia at .25 and well above 0, which is what it should be at. This is a good guideline:
ammonia = 0
nitrite = 0
nitrate = <25
Keep the 5 gallon tank for as long as you are in that dorm, then begin to upgrade once you have a place of your own. If you are really interested in the hobby, you can invest in multiple large tanks and participate in professional activities and services.
I watch the show Tanked a lot, and I recommend it as well. It is fun to watch and also quite helpful in terms of fish keeping.