10 Gallon Tank Is This Fish Combo Okay For A 10 Gallon?

[Surely]

I'm a beginner, I know how the nitrogen cycle works, I know how to check ammonia, nitrite, and nitrate levels, and all of the basics. I haven't set up my 10 gallon yet, so it might be a while until I start cycling my tank. But first, I need to get an idea of what fish I'm going to put in my tank, and then I'll start the cycle. Example: if I put corydoras, I'll need finer substrares. I was wondering if this combo was okay:

4 cardinal tetras, 3 corys, 1 guppy. It might be overcrowded, so I need a bit of guidance. (Should I remove a few of these fish? Should I instead have 3 corys and 3 tetras? etc etc)

 

[windrunner9189]

hello, it seems it's your first post here, welcome to fishlore!

with schooling species like tetras and cories, you want to keep them in groups of atleast 6. this way, you'll see more of their natural schooling behavior. this will make the fish feel safer and reduce stress, then further reduce sickness.
cardinal tetras aren't recommended for 10 gallons, they are too active. neither are most corydoras, they need more floor space to forage through.
if you want schooling fish, ember tetras and microrasboras (ex: chilI rasboras) are very good options. pygmy cories may work too, correct me if i'm wrong.

how about one of these options?

-8x tetras/rasboras
-2x guppies

OR

-6x tetras/rasboras
-6x pygmy cories

you may also be interested in shrimp or snails. they do a good job of cleaning up the tank, but the snails will be a little messier than the shrimp.

 

[guppgirl]

I would not do cories in a 10 gallon, there's not nearly enough swim room for a group, and they do best in groups of at least 6. Even pygmy cories I wouldn't do in anything smaller than 15. I know it's disappointing, I love cories and wish I could keep them in every tank.
My usual suggestion for a 10 gal is 8-12 microrasboras (genus boraras or microdevario or celestial pearl danios (galaxy rasboras). Tetras tend to need a little too much swimming room for 10 gallons.
For your bottom dwellers, I suggest either 2-4 nerite snails, or a colony of neocaridina shrimp (start with 10ish, they will breed and produce negligible bioloads for the most part). Dependinig on your water's pH and softness, you could also consider caridina (specifically caridina cantonensis) Bee shrimp. They do best in slightly acidic soft water, just like microrasboras. Your choice there really depends on how active you want the bottom to be. Shrimp are obviously going to be more active than snails, and I think snails are harder to keep with microrasboras as the fish prefer softer more acidic water while the snails need harder water for shell health.
Edit: saw you were considering guppies. My current 10 gal set up is 3 male guppies, 3 mystery snails and an excess of random pest snails (ramshorns and bladder snails). I like it, but it's not the most interesting. You could do about 3-5 male guppies, and shrimp or snails on the bottom, but I wouldn't do any more than that with the guppies because they're bioload machines (as are the mystery snails). And I wouldn't do mixed genders with guppies because you ~will~ end up with too many babies.