Was wondering if antibiotics, such as Erythromycin, cause foam in the aquarium if not properly removed? Also, how long will it take activated carbon to remove these drugs from a US 75 gallon tank? :bounce::bounce::red_mouth

Working off what Randyl had posted and other posts on the internet, I needed a cheap way to lower my pH until I can figure out a RO system and not be lugging jugs of water up 3 flights of stairs all the time. My tap water has jumped up from 7.2 to 8.2 in the past few months and it's not making...