This allows you to clean up the algae off the inside of the glass by making use of a magnet on the outside, so it's not necessary to place your hand into your aquarium. You are going to pay a bit more, even so the benefit is worth it. Think https://leadingdiscountpetstoreua53196.laowaiblog.com/36497307/the-5-second-trick-for-beginner-aquarium-checklist