Tank mates for nice betta? Need algae for bottom feeders?

So, I have a 10 gallon tank, its planted, with some amazon and argentine swords, and two anubias. I have 1 betta, the water reaches around 82 degrees, the heater (50 watts) is never on because the incandescent lights heat it up. There's a Marina S10, my betta got stuck to it once, never happened again. Works very well, and extremely quiet!
My betta is very passive, and, I know this was stupid to do, lived with another betta for quite some time in a 3 gallon. They didn't bother each other at all, or do that thing where they puff out their gills/fins. Long story short, one died after having its water changed and I moved the other to a 10 gallon.
The ph is high, the kit only goes up to 7.6, and the shade is darker than that, would that be an issue?
In mind for tank mates are tetras, ghost shrimp, snails, or corys. If I were to get snails or corys, would I need to have algae in the tank first? I wouldn't want them to go hungry, or would algae wafers work? There are no decorations, just plants, planning on getting more, would that be enough for tetras to hid in?

TL DR

10 gallon tank
Marina S10 filter
50 watt heater (never on due to heat from lighting)
Ranges around 78 (lights off) to 82 (lights on)
Multiple sword plants
2 anubias
Rocky gravel
Use CzO2 booster (is this necessary?) API Root tabs and Aqueon Water conditioner
1 very nice betta

Tetras, enough hiding places? Would 6 work in a 10 gallon?
Corys, need algae and need to be in groups?
Shrimp, what exactly should they eat? Should I worry about them reproducing? Also, is temperature too high?
Snails, which one is best? I've had apple snails before, but they wouldn't eat the wafers and died

Any other tank mate suggestions?

 

you can add really small corys like pygmys or maybe some julii's 4-5, they don't need algae just toss them tabs and they will do fine, also I suggest if your were going to keep using root tabs switch to seachem way better than api. also if those swords survive they will over take your tank

 

Corys might be a good addition. They eat the algae of the sides of your tank and plants and also any food that sunk to the bottom, so you probably won't need algae wafers. Tetras are not a bad choice but I suggest getting maybe 4. 6 maybe over crowding it. Zebra Danios aren't a bad choice. I've heard some may nip at fish with longer fins so I guess it depends on the fish as an individual. Good luck though!

 

Zebra danios will nip in schools smaller than 6. You could do a couple cories, they don't need algae and would be fine with leftover food or algae wafers, basically anything you could go with 5 or so neons and a nerite snail and a few ghost shrimp. Ghost shrimp don't breed easily so no worries with that, but they may be a snack for betta everynow and then. I would add a few more hiding places just until the amazon swords grow more. For cories just don't get emerald ones as they get bigger than others. Pygmy cories would be best, but if you can't find them that is okay as well. Good luck on everything!

 

I have not personally owned any of the suggested tank mates you are asking about for your bettas -excluding unwanted stow-away snails on some plants that got eaten by my dwarf gouram- but from my research I can say corys are probably not a good way to go for a 10 gallon, UNLESS you can get a hold of pigmy/dwarf or juliI cory.
Corys do best in small groups (most recommend having 4-7 in a tank) and the minimal tank size for them is usually 30 gallon, some can go in 20, but 10 gallons would be a bit small for any of the normal cory species. If you only buy 1 or 2 they are likely to be nervous and hide away a lot you'd never get to see them being cute foraging around for food. On that note, if you did get corys you'd also want to give them a cave of some sort, it can be a turned over flower pot with a hole in it, driftwood they can hide under, or synthetic store decor caves, or some denser plant vegetation might work to (my bottom feeder loved living under my anubia nana until he got to big to fit under it). All that said, every fish is different so if you did decided to buy corys there is a chance you get lucky and have some personable, non-shy ones.

My niece got a cory once (just one.. after her first try with a snail ended with an empty snail shell) she never saw it, it hid in the cave decoration all the time and never cleaned the tank like she's wanted.

 

I would do either 5 pygmy/dwarf/Venezuelan pygmy cories or 4 julii/false juliI cories. I don't do community tanks with bettas myself, but if you're going to try it out, go with bottom-dwellers who won't be constantly in your betta's face.

 

Thanks for the responses guys! I'll be looking for pygmy cories (LFS don't sell them, online a good choice?) I added 3 ghost shrimp to test my bettas friendliness, doesn't mind them at all! I did hear swords can easily take over a tank, good thing I got 3 extra tanks Trying to get a well planted tank