I setup this tank a week ago and did no research whatsoever until the fish started dying and so I started researching to find out why and found out about the "cycling" since doing research I have done a 25% water chance twice to lower ammonia and nitrite levels. I had two common pleco's and one turned completely white and died (not sure if white before or after dying) and the other one is starting to turn white on his head. All of the other fish seem fine and a lot more energetic since I've done water changes. I feel so guilty and bad for putting these fish in here without doing my research first but I'm trying every way possible to help them now. The pic is of the pleco. He is in a 55 gallon tank. Water temp is at 79 degrees. I bought a 5-in-1 easystrips test kit to check water quality and it shows 0 nitrites, 0 nitrates, soft water, alkalinity is 120 (says that is ideal), and PH is 7.2. Which these results make me believe the cycle has not even started yet Is there something I can do to help the pleco?? The white head is scaring me because I don't want him to die and all of other fish (at the moment) seem fine.