I am not sure what type of washer you have but with our front load washer our water bill only went up about $1 a month and we wash daily. 

Y do you have o change beds every night?  Are they soaking through?  I am sure you can find some cloth that works.  While ours doesn't hold every night I am much happier with the results.  For us huggies overnights would get so full that they would burst and I would have gel everywhere. 

I have found the best night solution to be an all fleece pocket diaper with a hemp pre-fold as an insert, with fleece jammies over. 

A fleece wrap over a well stuffed help nappy, or a fleece pocket well stuffed with hemp/bamboo, seems to get DD2 through most nights, as long as I remove it as soon as she's awake so she cant be a lazy tike & flood it instead of using the potty!