Water pH fluctuations
I have a question about water pH.
My tap water ph is 7.0 but when I add it to aquariums it goes down to 6.0. What is the reason for that? I have gravel in both aquariums, I use fake plants and moss balls.
To rise pH I was using seashells, pH with them in aquarium rises to 7.2 or 7.4.
What is best for betta? Low pH or better keep the seashells and leave it above 7.0.
What might be the reason of pH dropping, after adding tap water to the aquarium?