An easy way to save water is to wrap a brick in tin foil and put it in your toilet tank. Every time you flush, the bowl will fill that much less and you'll save a ton of water over time!

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I am not sure how new is new when it comes to toilets, but this has worked in every one I have had. Try it, it is simple enough to undo.

For more extreme measures I have lived in 2 houses where toilets were flushed by a "bucket flush" method. Five gallon buckets were left in the shower and outside in the rain to collect water and then this was poured into the toilet bowl directly to flush it. 

It seemed like a great way to save water, though we put them away when nicer company came!

I did flush the regular way once every other day just as a precaution, though I don't think it did any harm any way. Any thoughts?