Ok I come home today and find my baby Arowana (2.5in) swimming funny. Moving his head side to side almost like waddling in place. I did a 25 percent water change two days ago. I used prime for the water and my ph is 7.2-7.3 and my temp is 82.5. He ate a little plankton and whent back to it.I might be parnoid but I lost the last two Aro's to sickness so i really don't want to take chances. I had cross contamination with a sick pleco and my last Aro died after rubbing the glass at first and developing a sore on his head got sick and died. I treated the water and still have the pleco that looks good except for a mark I thought was scar from a scrape. should I hit the water with some mela or prima fix or just wait?