Hi- I️ have a 55 gallon planted with 9 guppies, 16 neon tetras, 5 kuhli loaches, 5 otocinclus, 5 cory cats, some Nerite snails, amaño shrimp and Cascade 1500 for filtration with seachem matrix as my bio media. Also have the Eheim 350 surface skimmer. Tank has been running since July but issues didn’t start until end of September. We had a Hurricane hit us and loss of power for a week. I️ was able to run the filter on a backup power source but not the lights for a week. Since then I️ have brown algae show up in the hoses and water looks like it has small particles in it. I️ have lost many guppies and a pearl gourami. They end up just sitting at the bottom for a few days before dying. One at a time with no visible disease. Before it was 1 every other week but now I lost 4 guppies this week. It might be unrelated but 1 cory has his tail missing. Looks like a clean cut, not fin rot. None of the other species seem affected. My parameters are 0 ammonia, 0 nitrite, 0-20 nitrate, 7.8 PH. I️ have tried using melafix, pimafix, UV sterilizer, and I️ just started Furan 2 today. Any suggestions would be welcomed. Thank you