The answer depends on whether your water provider uses chlorine or chloramine.
For chlorine, the best is API Tap Water Conditioner. This contains just two chemicals, one to remove chlorine and one to bind metals.
For chloramine, it is better to use a conditioner which also temporarily detoxifies the ammonia made by splitting chloramine.
The conditioners to avoid are those which contain something to "promote the slime coat" or similar wording. These additives can coat the fish's gills over time.
If the Tetra water conditioner is AquaSafe, I would use the bottle then don't get any more.
From Tetra's website
Removes chlorine; breaks chloramine into chlorine & ammonia then removes the chlorine; binds metals. Does not mention detoxifying the ammonia from chloramine so I wouldn't use it when there's chloramine in tap water.
This could well be aloe vera, one of the things that coats fish gills.