Old salt water
 

Does anyone recycle or do anything with their water change water? Just feel like it's wastefull to pour 20g every 2 weeks sometimes more often down the drain.

Not much use for left over salt water. You think thats wasteful? You should check out the waste to good water ratio of an ro unit. However if you wanted at least you could use the ro waste water for something.

Yea I sometimes use my ro for plants/the garden. Also has dual membranes on it. So trying to save some water those two ways. I can't think of many uses for old salt water but I'm sure someone out there might have found something

Nope other than recycling water from a reef tank to a fish only tank, there really is no viable option for recycling saltwater. If you add it to your plants, it will "salt the earth" and make it useless for growing anything in the future.

The high ratio of waste water to good water is the main reason I stopped doing RODI (as well as the high quality tap water in Greater Vancouver). I do 110g+ water changes on all my tanks at the same time, which means I would need 6 to 8 barrels just to store the waste water for using in my garden in the summer.

Saltwater changes
 

I have a friend and I will time from time to time water his yard at night. He know that I do it and he can't figure out why his grass keeps dieing.

I'm glad you're not my neighbor.

My water change goes on my driveway to kill any weeds and my ro waste water goes back into the ground where it came from

LOL... I actually did that by accident. Poured a whole bunch of saltwater out my back door onto my lawn.... well needless to say I was re-grassing the lawn last year.

I water it down and use it for my brine shrimp hatchery's :)

I use my old fresh water to water my indoor plants. And I'm going to try using my salt water for de-icing my sidewalk. The ladder was just an after thought... Which might or might not work.