You can use an smr1 just fine. What is more important is the type of pellet you use, they are not all made the same, despite what someone might tell you.
I use ecobak pellets, as I just started using them. After the months of research I have done, and phone calls I have made, ecobak is the way to go. Any issues or questions, and you can call them, and the owner/braintrust, Jon, will answer any of your questions. So far very pleased, minimal bacterial blooms, easy tumble rate, and you don't need a lot of flow like the others do. I invite you to research those pellets.