Is It A Parasite?

So, I have a 5.2gallon tank, as well as one male Betta fish in this aquarium. My plants are healthy, growing, and my fish shows nothing wrong.
So... Ive had the tank almost one month, and decided it was safe enough to begin siphoning the gravel and do a 25% water change after letting good bacteria build in the gravel. (I did not change the filter)
As the water settled and letting the water go back to its regular temps, I placed my fish back in. While watching him explore his newly cleaned tank, I noticed VERY tiny, small white... specs? However, the ones that werent floating around... some were on the glass of the tank, and wiggling?! They were moving in an uneven fasion, as if searching for a safe spot, and there was quite a few. Ive never seen such a thing! Its not an overload, but enough to spot a few on the glass, and similar ones being blown around.

Are they harmful? Could they have come from my live plants?
Am I over reacting and these guys are the 'garbage cleanup crew'? Even though I have no idea how they could have gotten there.

Here is a video... not the best, but you can see the tiny white blurs.

Tank Info
Tank: 5.2
Filter: Built in
Heater: -- 2-10gallons
Bubbler: Small 5 gallon bubbler, with smallest bubble stone

: Ball(x3) ... (x2)
Fake natural colored
Fake Rock decor with (x1)

 

Most likely all part of the web of life. When I set up my fry tank I encourage these tiny life forms as they are the first food of certain smaller fry such as Danio Fry (after they have spent a day or two absorbing their yolk-sac).

These are probably Paramecium.

Its not necessary for tanks to be sterile environments.

 

Are they harmful? Will they cause problems? What exactly do they do?

 

I was thinking about adding 3-4 ghost shrimp to my tank, as they aren't flashy and harder to see, so my Betta won't be drawn to them... will the Ghost shrimp eat them?

Or possibly a cory catfish. Either way.

 

I was thinking about adding 3-4 ghost shrimp to my tank, as they aren't flashy and harder to see, so my Betta won't be drawn to them... will the Ghost shrimp eat them?

Or possibly a cory catfish. Either way.

Shrimp should eat them but how open is your tank. Picture?

 

If they’re paramecium, they could’ve come in on your plants or from your water. Before you ask “my water?” you should have a look at it under a microscope. Or not if you’re squeamish. If you don’t overfeed they won’t get out of hand and the fish will eat them. Fishfor2018 is right, Fry love them.

 

I was thinking about adding 3-4 ghost shrimp to my tank, as they aren't flashy and harder to see, so my Betta won't be drawn to them... will the Ghost shrimp eat them?

Or possibly a cory catfish. Either way.

Go with ghost shrimp; cories will be a headache in that tank size.

 

This is my tank.
You can actually see the little white flakes, which is them on the walls of the tank.
Some of the plants are in fluval stratum, as I am waiting for them to grow to a larger size, before placing in gravel.
(eventually I think I may even just use fluval stratum as the substrate anyways)