If you are using this for an aquarium, it would be expensive but I am using this as a fertilizing substrate for my plants and it is a lot of product that should last me a while. The bag is a nice size and the product is in granules that do not break up. when mixed. I will be ordering again and I am so happy I found this! If you wet it before using it, never pour down the drain, use it to water your other plants instead of throwing it out, the plants seem to love it. You can also propagate in it.