Any bottom feeders for my betta?

Hey guys! I have 2 Betta tanks. One (first pics) is suspected to be a 2 1/2-3 gallon, and the other (second pics) is a 1 1/2. I was wondering if I could add any bottom feeders like any shrimp/snails/etc. Anything really. I'd also like the bottom feeder to be easy to take of. My Betta in first tank is really aggressive so not sure if there's any hope of that for him...? Second Betta is pretty calm for a betta.
Dimensions:
1st tank: 4" wide, 9 1/2" tall, and 15" long
2nd tank: circle, 8 1/2" circle. * from top edge to other top edge *
See pics.

Thanks!!!

 

The only thing I would add is a few shrimp or a nerite snail. If the betta is aggressive I wouldn't add anything, he'de probably bother the snail and eat the shrimp. You could add some cherry shrimp or a nerite, just keep in mind that the cherries might get eaten, and neither are bottom feeders.

 

Ah. Okay. I only want to get something to help clean the tank.

 

Ah. Okay. I only want to get something to help clean the tank.

What do you mean clean the tank?

 

Is there anything that eats poo or something? My Betta eats all his food, so no problem with leftover food.

 

Is there anything that eats poo or something? My Betta eats all his food, so no problem with leftover food.

NOTHING will eat poo, and it doesn't matter because the poop thats eaten will get pooped back out.

 

Lol. Okay. Thanks for your help

 

Yeah I wouldn’t add anything to either of em. 2 1/2 gallons is bare minimum for a betta so adding anything else would be pushing it.