Sand removal?

[Aquattro]

After running my tank for 7 months, it's become obvious that the sugar sand isn't going to stop clouding the water any time soon. I'm thinking of replacing it with a courser sand.
I'd like to remove it all in one go, so looking for ideas on filtering the water as I vacuum the sand out, so that it can feed back into the DT. Trying not to drain the whole tank