When storing saltwater???

[Srt4eric]

So I just got a 20 gallon brute and I've got about 10 gallons of water from Neptune's in it left over from the water change today. How long will the saltwater stay usable in that trash can on my back porch? Should I put a power head in the can to keep it moving? Should I keep a heater in there to keep it warm?

 

[Meshmez]

I keep my salt water in my containers in my garage for ~1 month before its used up. It's covered with a pump circulating the water. No heater, though I think I'm going to add one to turn on to heat the water before water changes now that it's getting colder.

 

[JVU]

You don’t need a heater or pump assuming it won’t get really cold before you use it. It’ll keep for a long time if it has a lid (keep out stuff in the air and keep evaporation down). You’ll likely get a small amount of inconsequential bacterial growth which can cause a little smell.

 

[IOnceWasLegend]

I keep my salt water in my containers in my garage for ~1 month before its used up. It's covered with a pump circulating the water. No heater, though I think I'm going to add one to turn on to heat the water before water changes now that it's getting colder.

I would also add that it's not a bad idea to check the alkalinity and salinity prior to a water change. Alk declines over time, and evaporation could change salinity.

 

[jccaclimber]

Once upon a different locale I used to as a rule keep pre-mixed salt water on hand equal to the volume of my display. As mentioned, keeping it covered is a good idea. If nothing else it discourages bugs from getting in and dying. Doesn't hurt to keep the dust out, but then again I don't have a lid on my tank, which is of greater surface area.
A lid has the added benefit of keeping evaporation down, but check the salinity later just in case. That or mark the container now and just add RODI back to that mark when you use it.
Depending on what salt you are using alk will fall, so check that, but nothing else will change enough to really matter.
If you throw a bubbler or circulation pump pointed toward the surface it'll keep it from getting that enclosed humid space smell, but that's yet to cause me any issues so I typically don't.

 

[Vincerama2]

You don’t need a heater or pump assuming it won’t get really cold before you use it. It’ll keep for a long time if it has a lid (keep out stuff in the air and keep evaporation down). You’ll likely get a small amount of inconsequential bacterial growth which can cause a little smell.

THose (evaporation, bacteria) seem an even better reason to NOT heat the water!

 

[Meshmez]

My thought for heating is to only do it right before water change in order to match tank temp.

 

[ashburn2k]

My thought for heating is to only do it right before water change in order to match tank temp.

or get a MAG pump, those will heat up the water while mixing.

 

[jccaclimber]

or get a MAG pump, those will heat up the water while mixing.

Durable like a Mac truck, but not much more efficient.
I ran the numbers a couple years ago, for people who don’t need to hear their tanks (read:when I lived in Texas) even an Abyzz had a lower 10 years total cost of ownership than a MagDrive. That’s with much lower electrical costs too.