How long has the tank been set up/cycled and up and running?
How long has this cloud been appearing?
Test your ammonia and nitrites. Let us know the results.
Cloudy water can be from:
Bacterial bloom: white hazy cloud, population bloom of Heterotrophic bacteria because there is excess organics in the water. They break down organics into ammonia, so ammonia spikes would be present if cloud is present. Vacuum/clean out excess organics (uneaten food, debris, detritus, etc.) to remove Heterotrophic bacteria food source to subside the bacterial bloom. Do water changes as necessary to remove organics and dilute ammonia levels.
Physical debris particulates: just need fine pore mechanical filtration media to catch/collect the tiny particles out of the water. Harmless to livestock.
Precipitation: some reactions happening, which I think are not harmful. Just give it time to naturally settle itself out.
Green water: algae free floating in the water column. UV light can eliminate green water. Or can do blackout. Or address ammonia or nutrient problem if that is the cause.
From what I hear, co2 micro bubbles won't make the tank cloudy, but the tank will look like a carbonated beverage with little bubbles everywhere (Sprite, etc.).
Just looked up Clarity and it basically just makes particulates larger so coarser pore media can catch them. And since you are still having the cloud, I kind of doubt it being physical particulates. But there is still possible the particles are still too small to catch for your media or there is so much of it coming from your substrate being disturbed.
I overstock a lot and don't get any cloudy water, so that wouldn't be a problem if your tank is appropriately filtered and well established.
Well the biggest thing to check if the ammonia and nitrites, that will narrow things down.