View Full Version : Waste water into usable energy?

06/06/2016, 04:47 PM
I know this is a long shot, but has anyone ever taken this idea and used it?

Some are just dumping the used water after a water change into the drain anyway, might as well put it use?

* Charge batteries to use in case of a power outage?
* Power low wattage lights in the house?
* Run a bunch of these in series to possibly power your tank?


06/06/2016, 06:53 PM
Eh.... it's a basic galvanic cell.
The saltwater itself does not generate or contain any energy, it just serves as an electrolyte.

06/06/2016, 08:43 PM
Right, I got that part. You need other components like copper and zinc, but the constant changing of the salt is something we are throwing away anyway.

06/14/2016, 04:24 PM
I use to give my water from my reef tank to FO tank guys and it saves time, money and ecologically smart.

My nitrates are extremely low, I change water mainly to keep my Ca/Alk and trace elements on check.

06/15/2016, 09:31 AM
So what's your thought here? Run it down a water wheel or something? I'm no electrical engineer, but I don't think even a few dozen gallons from a water change would produce any meaningful energy.

06/15/2016, 02:49 PM
I ran my ro/di wastewater into a toploading washing machine, always ready for use. No problems. You can also use it for watering house or garden plants, any reasonable domestic use. The only reason you shouldn't drink it is that the container probably gets bacterial growth.

Now, if you mean your salt discard water, sure, you can use it to wash pumps, gear, etc, no reason not. Use it for weed or plant killer in an area where you don't want stuff to grow, like driveway cracks.

06/15/2016, 03:08 PM
My water change water typically goes down the toilet. Like sk8r mentioned though, does wonders for weeds. Kills poison ivy with a quickness

I use RO waste water to water my houseplants and tomatoes and have no qualms with it.

Doubt there is any feasible, efficient way to gather energy from either though, if there was, considering most reefers are extremely creative inventors, someone would have done it by now.

06/16/2016, 12:50 PM
All that video does is basically make a homemade battery. Not practical for any purpose other than a little fun. You can buy kits online that all you have to do is add saltwater.

08/08/2016, 01:44 PM
The ecological costs of manufacturing and employing the galvanic cell would be orders of magnitude higher than the ecological benefits from offsetting a fraction of your energy consumption through such a system.

Penny wise and pound foolish.

11/18/2016, 09:00 PM
I use to give my water from my reef tank to FO tank guys

This is very neat... a pass-it-down scenario. Next if you could desalinate it, you could give it to FW or planted folks.