It looks like you are into Red Cherry Shrimp; I was given a "starter pack" of that variety a couple years ago and they have multiplied like gangbusters. I've pulled out several hundred at a time on multiple occasions and it hardly seemed to make a dent in the population. Mine seem to do better at closer to 70F rather than 80F. Bacteria will still be fine at that level, and the sponge filter you are using is perfect for shrimp since it will not endanger the smallest youngsters and provides excellent biological filtration, as well as a fruitful breeding ground for micro-organisms upon which the shrimp will feed. The addition of some Java Moss would be nice; can't think of a more perfect pairing for small aquariums than shrimp and moss. A mass of floating plants like hornwort will also give a nice look, and numerous shrimp will hang out near the surface when there is a bunch of plant material there in which to rest.
I've read that shrimp are sensitive to changes in water quality caused by large-volume water changes. All my tanks get large water changes frequently, almost never less than 60-70%, and my shrimp have never seemed to suffer for it. I think that when the changes are frequent enough (weekly or better) the water is always fairly close to brand new in terms of parameters, so there is no drastic swing for them to adapt to.
Good luck with that nice little tank. It looks good now; it'll be stunning when those plants really start growing in. And the first time you spot a tiny new shrimp that has hatched in your tank, you won't be able to stop grinning.
