In general, algaecides are not recommended. While it helps clear up the algal blooms, dead algae can severely cut down the oxygen level suffocating the fish almost immediately and even crashing the water conditions. It is for this reason we suggest that you refrain from using it. If you have to, you'd need to check your water parameters fervently, do water changes as necessary and cut back on the foods until you restore the conditions to normal.
Right now, ammonia is not the issue but nitrite is as I had suspected. At this point, please add a teaspoon per gallon of sodium chloride. Any salt in that formula is fine, whether iodized or not, as long as it does NOT contain yellow prussiate or ferrous cyanide. Kosher salt, pickling salt, rock salt, iodized table salt or "aquarium" salt are absolutely fine.
What plant do you have? Get a terracotta pot and stuff some gravel there. Put the plant in the pot. In the meantime, you can gradually reduce the substrate until you go completely barebottom if that is what you plan to decide. You can stuff a cup of gravel in a nylon bag temporarily and place it in your filter (if there is sufficient space) or locate it in the corner of the tank to avoid cycle bumps. Once water conditions are restored to normal, ditch that nylon bag of gravel out of the tank. You can still maintain barebottom setup with plants if you can keep floating plants, plants attached on decors or potted plants. My tanks are done this way and maintenance is far easy for me.
