I shudder to stick my nose here. As most don't get my thought process
PH up should be common baking soda salt combo IMO.
Never ever an off the shelf product unless you are experienced and can read the ingredients.
And then you likely would not buy it.
never ever do more than a extremely small change in ph per day.
You will likely be fine but it COULD cause chaos for one or more fish.
No matter how cheep and small I'd like to see great care for all.
When messing with ph take a bucket and test the results b4 you mess with your tank.
It is one of the most seriously reacted to by your fish parameters short of a high ammonia , nitrite reading.
Why exactly did you end at 6.0? or is your water starting there?
How would we be able to make sure you don't see this again?
these are the questions we need to address here.
can you detail history? maybe use this
form omitting the non useful info.
Modifying up is what i do with my Africans..