Without knowing exactly what it is, it's a little harder to say, but, in general, red plants might need some special substrate or fertilizer to get the best from them. Usually, you'll find that a good aquatic soil supplement will contain all the right plant nutrients, including a form of iron.
In some places you might go to read about it, the jury is out on the extra iron for red plants anyway. Some will swear by it and others will maybe have never added it ever and still had great results!