I have had mine for two years. They get their nutrients from the water column. I dose flourish excel daily, flourish comprehensive weekly after my water changes and I dose flourish potassium three times a week. The Madagascar lace fern needs potassium. Looks like your is doing just fine with what you're using. The leaves on it will keep growing and growing. I have cut leaves off of mine longer than three feet. Occasionally it may go dormant on you. If it does just let it be and it should sprout back up after a while. If it doesn't come back up after a while (like six weeks), pull the bulb out, put it in a plastic bag and throw it in the crisper drawer of the fridge. Then just replant it and it should come back. As far as light, mine is in a 56 gallon column tank with 96 watts of t5ho light. Not exactly high light. They are prone to algae so if you have too high of light it will grow in the leaves "netting". I have three Siamese algae eaters in my tank to eat the algae off of my leaves.