That sounds like a great start. Give the media a couple weeks to work while continuing (smaller) water changes. You need to let the rocks leach the phosphate and that will probably take longer than a week.
The sawdust could have been a big part of the issue but a bigger issue I see iis that you said the sanding took place months ago and you are just now finding it. You should clean mechanical filtration much more often than that.
The sawdust could have been a big part of the issue but a bigger issue I see iis that you said the sanding took place months ago and you are just now finding it. You should clean mechanical filtration much more often than that.
