Yes you can use it by itself or use it with another substrate. I've used it with other substrates with good results. Most people mix it with another substrate but I don't see why you couldn't use it by itself.
Well the I'd like to see if I could use it with just a plain gravel instead of capping it with like, eco complete say for example. would it still be as affective?Yes you can use it by itself or use it with another substrate. I've used it with other substrates with good results. Most people mix it with another substrate but I don't see why you couldn't use it by itself.