I have an "experimental" 10g running, sand substrate, full of plants, heated. Originally no filter, no light (it's in a west/southwest facing window). Small fish at the start, 9 Boraras brigittae
, 7 Corydoras pygmaeus
, 1 Dwarf Puffer
(unexpected arrival with something for another tank), 2 shrimp (also unexpected, came with the pygmy corys). Weekly 40% water change.
After a couple months, I added a sponge filter. Not exactly sure why, there was just something not quite right. Glad I did, it is much clearer now. I removed all the named fish, since I used this tank for my Farlowella fry that need fresh algae and with the window I thought this was the best way to get it. Also added a CF light fixture with 2 10w daylight CF bulbs.
The point of the above story: small fish work in such a setup better than larger. Water quality is one important aspect, but so is the physical space. Rams (I assume you mean the common or Blue Ram
, not Bolivian Ram
) should, as noted in our profile, have at a minimum a 24-inch tank, a 15g or 20g. They are territorial fish, the male establishes his territory, and between spawning he might (I say might) take a dislike to the female. She needs somewhere to go out of his sight, and in a 10g that is not going to happen.
I would agree that on their own, a spawning pair in a 10g, well planted, no other fish, would work. But not long-term, and not with other fish.
Plecos are high-end waste factories. A 10g is too small for any species of pleco, in my opinion. Shrimp and snails work better in such small tanks as "scavengers." My 10g now has i don't know how many hundreds of Malaysian livebearing snails. Not sure what they are eating, I add no food to this tank, as the Farlowella fry eat algae and nothing else. The puffer all but eradicated them, but since he left they have reproduced big time.