A started this tank around 4-5 weeks ago and it’s a planted tank only with no fish in it neither a filter or heater. I dose it with fertilisers every week with 5ml. A week ago it wasn’t so bad. I’ve never fed the tank and now their could be thousands on all sides. They usually go under substrate after a few hours of the light turning on. Please help it’s my first planted tank. I have another tank 75 gallons but never had any of these problems. There are also snails (hitchers from plants). I also have no intention to put fishes in.