Betta tank - the snail died - maybe shrimp?

[Suda Nim]

Background: I have a 5-gallon planted tank with a betta. The pH has been pretty consistently on the low side: 6.4-6.6. Ammonia, nitrites, nitrates, are all low, temperatures is a steady 78-79 degrees. I have a HOB AC20 with a flow baffle and do a weekly 1-gallon water change (about 20%).

The tank has a light layer of brown algae on the plants and a whitish fuzz on th edriftwood. No other algae.

I started the tank with the betta and an apple/mystery snail, which I fed on algae pellets, carrots, lettuce and other veggies. The betta occasionally poked at it, but I took it as curiosity rather than aggression; the betta never bit at it.

The snail died over the weekend. I don't plan to replace it because I don't know why it died (also, TBH, it was more work than the fish was: blanching and weighting veggies, fishing them out, fishing out uneaten tablets, etc).

But I'm thinking about shrimp, since the betta seems to be fairly peaceful. Are these water parameters suitable for shrimp? And with not much algae, what would I need to feed them?

[Suda Nim]

I just realized this would be better asked in the Shrimp area. I'll repost there. Please disregard this post.