Medium planted tank that had 3 ottos a golden pleco and a spotted Raphael cat. I’m the past 2 days all ottos and the pleco died. Also an infestation of tiny micro scopic mites have appeared that are attracted to light and swarm pleco wafers. I have done multiple water changes over the past 2 days vacuumed gravel but now the Raphael is starting to lose its black color and get reddish areas on him. The tank is 10 gallons with an aqua clear 30 power filter. Substrate is fluval stratum on top of gravel and the tank is heated. I have already turned the tank temp up and turned the filter to a higher setting. Please help!!!