Well, depending on the unit, RO wastes a gallon or more for each gallon purified. The amount used for your tank is a drop in the bucket, so to speak, compared to showering, washing dishes, etc.
Nonetheless, some battles aren't worth fighting, especially with a mother. If your problem is contaminants coming in from the tap, you have a couple of options. One is to fill a section of PVC pipe with activated carbon and run the water through it. You could also try a bag of carbon in the sump or skimmer. One other option, which is what I did, was to buy RO water. Our local co-op had a system, and I'm sure you can find something nearby.
Nonetheless, some battles aren't worth fighting, especially with a mother. If your problem is contaminants coming in from the tap, you have a couple of options. One is to fill a section of PVC pipe with activated carbon and run the water through it. You could also try a bag of carbon in the sump or skimmer. One other option, which is what I did, was to buy RO water. Our local co-op had a system, and I'm sure you can find something nearby.
