Having an RO or RO/DI unit can save you some time, money, and relieve you from having to lug five gallon buckets to and from your local fish store (LFS) on a regular basis. However, along with many benefits they do have one main drawback, an excess amount of waste water. It is common practice to expect approximately three gallons of waste water for every one gallon of fresh RO water. With the significant amount of waste water produced, aquarium owners should be searching for clever ways to utilize the excess water produced. Here are a couple of ways one might consider when trying to find a use for the RO waste water.

1. Water the plants in your house. (I use this method most often)

2. Set up an outdoor containment tank to hold large amounts of water for use on your lawn.

3. If you have both a fresh and saltwater tank, use the water to fill up a fresh water fish tank.

4. Plumb the waste water into your clothes washer. (Interesting, and just heard about this one the other day)

5. Try and curb the evaporation in a hot tub or pool during those hot summer days with the excess water.

Just remember that if you do nothing but run the waste water down the drain it will be just that, waste water. Everyone should try to find an alternative use for the excess water, whether it be one listed above, or by coming up with a new application on your own. Please do the responsible thing and recycle.