That's quite often! Good on you![]()
If you spot clean, OP, the vive stays much cleaner for much longer. I think, depending on how much aspen you have down, you can change about once per month. If you have a very thin layer then more often may be needed. I have about an inch, and change it once a month plus spot cleanings every week. Although I'll admit, it's more difficult with a PVC cage than a glass tank that had a clear bottom!
You should start to notice when it needs a changing. If things start smelling funny, that's a sign.![]()