aluminium potassium sulphate and copper sulphate crystals

[mtg]

I have heaps on CuSO4 and AlKSO4 waste crystals and I was wondering if anyone has a prac or activity that would use it all. I wonder if we could make a big crystal with it all, as I've seen huge CuSO4 crystals. if I dissolve it all and evaporate some of the liquid to concentrate it a bit would the seed crystal theory work? Otherwise where do you get rid of it, seems overkill to send it off for chemical collection.

[Merilyn1]

I'm stuck with heaps of copper sulfate waste, too. I've evaporated it down and could use it to make a saturated solution, but we never seem to need it here. I also have a couple of winchesters of mixed copper waste, but I know it is mostly c/sulfate. I have left it in a beaker to evaporate, to reduce the volume, which helps. I can't put any down the sink because of the septic system - so the usual methods are no good as there is still a chance of residual copper going down the sink.
At this stage, I am just sending it off for disposal.

[Milo]

There are ways to treat copper sulfate to make it safe for disposal. One I've heard mentioned is putting steel wool in it, although I haven't yet tried it myself. There's a recommendation for this on Science Assist:
https://assist.asta.edu.au/question/431 ... id=3be8dee

[Smithy73]

Once you have grown your copper sulphate crystals and finished looking at them you can grind them back to a powder and store them away for next time. Saves on a lot of waste. We have done this for a couple of years and haven't had any issues with them reforming, I also keep some whole as seeds if needed.