Problem is that one of the experienced people on here said that as a beginner I should really not mix fish but go with a one-species tank. But I have the problem that I won't be able to have another tank, all the space is used up with this one, even if it's just a 10 gallon. And I'm really interested in both these fish and they need much the same water parameters. Ideal for the soft water. It sounds like a lot of fish but they're tiny, total inches when adult would be 8.25 out of 10 (if that rule is any use) and aqadvisor says I'd be at 76 percent. Cories need to have nitrates under 20 ppm so live plants should really help with that, I understand otherwise their barbells get infected. And I started with a sand substrate specifically because I wanted the cories.
I think I can understand the thinking behind a species tank given the size, but I do not agree it is your only option. In my fish room of 8 or so tanks I have a 10g, and for several years it housed a group of 9-10 pygmy cories, 11-12 Boraras brigittae (chili rasboras), and plants and snails. It had no filter. Sand substrate. Ember Tetra are the same impact biologically as the dwarf rasbora, so I see no issue at all.
Forget any calculation of fish size/number/volume. While it may prevent beginners from overstocking, the calculation quickly breaks apart because it does not consider what really matters. And that is
1. the fish species being in sufficient numbers to avoid stress which causes additional impact on the biology;
2. the appropriate aquascape for the species so they have what they "expect" because this is programmed into their DNA and without it they will be stressed,
3. the appropriate water parameters (GH, pH, temperature) because this will allow them to function as they are designed and that means less stress and less biological impact,
4. free of stress from other sources than those listed above, such as inappropriate tankmates that could harass them and keep them stressed.
EDIT. Wanted to suggest you get more of both species, at least 8-9 habrosus cory, and same for the Embers. More is always better for the fish, and it lessens stress which means less biological impact.
Thanks for your explanation about the Java Moss and the Anubias and Java Fern. I understand that pots is not so often done. The thing is the fish I had really, really set my heart on in the tank was 5 corydoras habrosus and 6 ember tetra. I was worried the cories would burrow up the plants, and I also don't have a super thick layer of sand,, I have 0.5 to 1 inch, so it is easier for me to take care of. Not deep enough to plant plants in. And the little pots would help me take better care of the plants when I have to pull out dead leaves and such, and I could rearrange things now and then. I chose acrylic so you could see the natural material through them.
Pygmy or habrosus cories will not uproot plants once they are established. The 10g I mentioned above has pygmy chain swords spreading all over the place, with just 1 inch of play sand. Plants in the sand are important for the health of the substrate, and the substrate is the single most important aspect of an aquarium because that is where the majority of biological activty occurs--not in the filter which as in my case didn't even exist.
So should I be using sand in the pots instead of the Seachem Onyx Sand I got? (they didn't have any substrate for plants that wasn't black). I read online that I should put a layer of gravel on top to keep it from clouding the water.
I really wouldn't go the pot/soil route. A tank this small really will benefit from nature, plants in the sand, or just floating plants.