Here's my tank rn. I have 1 gold zebra loach, 5 neon tetras, 1 betta, 3 corydoras (I know I need to add more, but I don't know how many. I don't want to overstock my tank) in a 20 gallon high. I came from vacation the day before yesterday. I was gone for 2 weeks. Used automatic feeder. I did a water change the day before going to the vacation. I kept my lights off the whole time. Usually, I keep my light about 13 hours. ( 7Am to 10PM.) is the light too much? I'm going to test my waters, so the result will be in a minute. How should I stop making this much algae, and what was the problem? Plants: 2 java ferns, 2 Anubias bateri var nana, 1 anubias bateri, few bacopa caroliniana, 1 amazon sword, thinking to get more plants and a bit more corydoras. Is the nitrates 10 or 20ppm?