My tank is 15 gallons and currently houses 4 juvenile pea puffers. I have several plants in the tank with them, including anubias hastifolia, cyperus helferii, microsorum pteropus, hygrophila pinnatifida and echinodorus ozelot red and a bunch of hornwort. So my issue is they become algae covered and the leaves all start to die off and every week I remove bunches of hornwort which is just dead and covered in algae. The microsorum flourishes, for some unknown reason but the rest fails. However, I have a 5 gallon which houses a single betta and a mix of snail species where the plants flourish and I am constantly having to trim them back. Could this have to do with filter flow blowing onto the plants? I do weekly 50% water changes and have experimented with changing the amount of time my tank lights are on, which is about 10 hours a day currently. I have never used ferts or CO2 but I am up for suggestions. Could anyone help me out?