Hi everyone, I've been a member for a couple years, but I think this is my first post. I was wondering if the alga i've attached pictures of is staghorn. Can anyone confirm or deny this? I set up a new tank (120 gal, 4x96W PC - Lots of light, but I inject CO2 using a mazzei and religiously dose EI) and I added a bacterial innoculant for ponds instead of one for aquariums, and within 2 days i had this alga growing everywhere. It can grow about 3-4 inches per day. I use a DC (KH4), and since i have no fish in the tank yet, i have increased CO2 to keep the DC yellow. The pictures don't indicate this clearly, but it is a dark brown colour, and i was under the impression staghorn was green-grey. Thanks for your help, and any suggestions on it's elimination!