Of course if you have an R.O. unit, you can top off with de-mineralized water. That doesn't get the fishy waste products out, but does keep the concentration of "traditional" water minerals from getting critically high. That sounds odd because without some calcium, potassium and magnesium, the fish will not develop strong bones and an effectively working neurological system. Too much mineral and they will have difficulty breathing though. For a little more on that, check out Winter Mystery Deaths in Immediate Help.

If your tank top will support a gallon jug or two, you might put them up there a few hours before your water change. They will make the heater work a little harder, but will gradually be brought close to the aquarium's temperature.

Wanting to take some gallons of water with to a fish show this last weekend, I even considered leaving them on the dining table, but that is not "my" territory. After a little reflection, I simply packed the couple of entries in fairly full plastic bags; also packed a bottle of Amquel in order to add a strategic drop to their water and trusted the quality and temperature of the (450) tanks at the WAKO killifish show in Milwaukee.

Having several aquariums I increasingly am storing water in 55-gallon food quality drums (for tap water) and a well weathered 32-gallon Rubber Maid trash can, which has always been used for fish related stuff. The latter container is at the end of about 20 feet of quarter inch tubing that was run from the R.O. unit in the laundry room through the wall and into a sheltered spot in the fish room. (Worry a hole in the wall with a screw driver rather than a drill - in case you come near to any wiring.) A 200 or 250 watt submersible heater goes in each. I'm thinking about dropping an air stone from the over head "track" of piping which is slowly being assembled. Each water holder is set upon fairly thick styrofoam sheets (former fish shipping boxes.) It is cold on that floor!

And I've got to move a couple of gallon pickle jars of plants off of that floor too. If tropical, they can be shocked or stunted from too cool temperatures, somewhat like the fish.

Would it make sense for you to dedicate a 3 or 5-gallon bucket (those cheap, clean ones from places like Menards aren't too expensive) serve your needs? Ask your pet shop if they have a broken fish box or, in the event of one breaking, if they would save the pieces for you. If a builder is putting together a house nearby, look in their garbage dumpster to see if they tossed some useful pieces of wall insulation board or green board. Don't just rip them off, that is expensive! :)

You might put a 50 watt submersible heater in that bucket. If you could install a GFI wall socket where you would plug in that heater's cord, that would be wise (as would running a tanks cords to a Ground Fault Interrupter).

Do remember to unplug the heater before taking the bucket away for a water change. ;)

Our fish room is seasonally heated to between 78 and 72 degrees F (22-26C). With the guppies, I need to tweak that up a bit. Placing the guppy tank high on the stands and remembering to close the room's doors would help too.

For cooler water fishes, the water can be set upon some old stools in buckets or those 5-gallon plastic bottles used with water coolers (and snapped up at garage sales). I often leave them overnight for use the next day.

I'm beginning to place larger aquariums on styrofoam sheets too. They are shipping material which would otherwise get tossed, ultimately into a landfill. That puts some space between a couple of 29-gallon tanks and their metal, cold conducting frames. It also eases structural stress if the stands are uneven or not quite level. One still wants to set them up as level as possible.

If you have an over-under aquarium stand and a tank only on top, you might be able to place that bucket upon the bottom level. That isn't too attractive though and is a definite no-no if there are small children in the house. If there was room in a cabinet stand, that might work.

When a college student, I got away with leaving a 20-15 over and under full of swordtails by my parents' furnace, even though it was in the basement. That only works sometimes. And swordtails are pretty tolerant of the low 70s.

Would that bucket thing work? Orchid growers also have the heated cloth they use to keep the plants above 60-something. I also saw a Betta person use that with his jars, though that might be a little risky.