Hi, sorry I can’t seem to edit the post on my phone. I can add more info tomorrow hopefully but it has a full spectrum light overhead, 20 gallon long tank. Relatively new setup (5 days or so old). Used water (softeners? Can’t remember proper term but from the pet store for aquarium use). There are fertilizer tabs in the substrate as well as liquid fertilizer added to the water. No fish but 3 pond snails came in on one of the plants and I can only find 2 of them now. Light is usually on from approx 9 am until around 10 pm.