FWIW, I don't think sand is a great medium (substrate) for rooted plants; I think there are problems with the grain size, etc. . . . I have found the best success either with substrates made for planted aquaria (eco-complete, flourite) or with laterite mixed with very small gravel
maybe you could improve results with fertilizer tabs that go in at the roots; I wouldn't bother with liquid ferts, since you have rooted plants . . .
maybe you could improve results with fertilizer tabs that go in at the roots; I wouldn't bother with liquid ferts, since you have rooted plants . . .
