Ok well my tap water is 7.0 and I understand I need to get it up to like 8.0 for africans. Well they have been in 7.0 there whole lives(pet store) so is it necesary for me to bring it up to 8.0???? If I do need to raise ph with substrate then what will happen when i do water changes with my 7.0 ph tap water????? how do i prevent those changes in ph???