In the middle of december I purchased a nicrew led light for my just planted amazon swords in my 29 gallon, and the growth was explosive. I'm talking growing over a foot in three weeks without ferts or tabs. I bought 3 little amazon swords, about 6 inches each with 3-4 leaves, and now, two months later I have about 8, 1.5 foot tall plants due to some of them producing so many runners. About two weeks ago I added flourish tabs because of there growth. Why are they growing so fast? I'm not complaining, I love it, but I thought the nicrew led was proven to be low light, and that swords needed medium to high light to grow this fast. I don't use co2 and the substrate is black diamond blasting sand. I have the lights on for 10-12 hours. No algae.