Hi Suya1,
Ouch !!!
I' ve searched for some informations about nanotanks, the biggest seam to be 24gal. am i right ?
Anyway, it's much too short for your actual population as situation will soon become unbearable for your fishes and for you : water parameters instability, suddent no2 pikes, territorial "wars", stress...
Let's try to find some solutions (if possible for you) .
Should go back to pet store (or friend's big tank) :
Pleco- adult : 2 feet tall !
Clown loach - adult : 1 foot tall, gregarious.
blue gourami - adult : 6 inches tall, territorial, real tough fighter.
Zebra danios - Fresh water dwellers (max. 24C°) very good swimmers (need a mini 3 feet tank facade), gregarious : at least 7/8 specimens
Neon tetras : idem as for danios, except for temp.
Done.
Now, you could upgrade your cory population, as they're gregarious, too.
Around 6 would be ok.
You seem to love gouramis, in your tank, it should be possible to keep a little harem of chuna or lalia.
10 caridina japonica
And that's all !
All of this according to compatibility with your water parameters.
Have you been advised you in your population choice by your pet seller ? If this is the case, is real job seam much more like " fishmonger".
Otherwise, i'm very glad to know that my tank pleased you.
It took a year to be "watchable", it's now far from beeing strictly beautifull, but more important to me : liveable and, i hope, friendly for my animals.
You can call me Pickerel or Dom, as you prefer.
Here in France, most commons botias are relatively easy to find, and a bit expensive, varying from shops to shops. For exemple every shops have clown to sell, range of price beeing between 3 to 12€ (3 to 12$). Sources are always open secret, everyone knowing they come from german, czechs or thai breeding farms.
Striatas/lohachatas are rare, within the same range of price, but more and more tiny. sources unknown
Kubotais, modestas, tiger ... very very rare and very very expensive.
Never seen any Hillstream loach in 20 years, though some french aquarists(?????) keep some.
I like tanks firstly because : it's beautifull !
Don't be too worried about your overpopulation, you've got solutions (not compulsorily mine), as with carefully choosen population and layout, a small tank can really be beautifull.
Cordialement,
Dom