Do you filter your salt water mix before a water change?

I use Reef Crystals and usually make 15 gallon batches for water changes. I circulate the water with a power head and aerate with a bubble stone for at least 24 hours prior to the water change.

In the past, I would always have a brownish scum stuck to the tote at the water surface at the end of mixing. I also always had this brownish color to my sand bed surface both in the DT and in the refugium. Kind of like diatoms but not quite.

Came up with this DIY filter for use when making my batches. I've been using it for about 2-3 months, and my sand bed is "brownish stuff free". I would also say that my WC water is much clearer than before filtering it. It's easy to make and pulls a lot of "crud" out of each batch. If you haven't filtered your salt water mix, you might be surprised at what comes out. I have not tried this with other salt mixes.

Take a piece of 3/4" PVC and cap one end (longer the better, but a 6-8" piece should work. Mine is around 12"). Drill 6-8 1/4" holes in the pipe near the cap.
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Cut a filter sock (or similar fine filter cloth) in a strip wide enough to cover your holes and zip tie it to the PVC pipe making sure the holes are covered and the zip ties "seal" the ends.
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Place the pipe in your mix bucket with the air stone in the pipe. Make sure the open end of the pipe is at the water surface or slightly under. The air bubbles will rise up the pipe and create a chminey effect similar to an undergravel filter. It will pull the water through the cloth and up the pipe. With that, you get both aeration and filtration in one step.
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Here's a filter after one 15 gallon batch mixed to 1.026 and aerated for 24 hours.
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