Changing Water In Winter

[fishlette]

i was just pondering the upcoming winter and was thinking when i do my tanks in winter how will i make the water warm enough before i put it in the tank? im guessing putting water in straight from the tap would be too cold. can i mix warm and cold water with a thermometer in it so i can mix it to the same temp as in the tank? any suggestions would be appreciated

 

[fishbone]

I always fill from the tap, mixing hot and cold into a 10litre bucket, add dechlorinator, swish it round. I don't check with a thermometer but make sure there's not a huge difference in temp by touch. Haven't managed to kill anything off doing it this way.

 

[MHunt]

Yeah, checking the temp by hand is adequate, and in any case, if the water change is only 20 or 30 percent, the water you're adding wouldn't change the temp of the tank too much. A cool water change is even useful to encourage fish to start spawning. It work's nearly every time for my cory's!

 

[vinylman]

I always fill from the tap, mixing hot and cold into a 10litre bucket, add dechlorinator, swish it round. I don't check with a thermometer but make sure there's not a huge difference in temp by touch. Haven't managed to kill anything off doing it this way.

It's best to use boiled kettle water to bring it up to temperature; hot tap water comes through copper pipes.

 

[MHunt]

I always fill from the tap, mixing hot and cold into a 10litre bucket, add dechlorinator, swish it round. I don't check with a thermometer but make sure there's not a huge difference in temp by touch. Haven't managed to kill anything off doing it this way.

It's best to use boiled kettle water to bring it up to temperature; hot tap water comes through copper pipes.

So does your cold water! But i guess hot water can absorb the metal easier than cold.

I always mix straight from my hot water tap, it comes direct from my combi boiler so doesn't sit in an immersion heater before being used.

 

[andywg]

im guessing putting water in straight from the tap would be too cold.

Unless you are doing very large water changes you are guessing wrong. I (and a few others) do 40% water changes throughout winter without using any hot water. 20% is perfectly fine with water straight from the coldest of Scottish water mains in winter.

If you e really worried, just have the water enter a little slower to let heaters warm the water up (assuming you have heaters in the tank).

 

[rdd1952]

im guessing putting water in straight from the tap would be too cold.

Unless you are doing very large water changes you are guessing wrong. I (and a few others) do 40% water changes throughout winter without using any hot water. 20% is perfectly fine with water straight from the coldest of Scottish water mains in winter.

If you e really worried, just have the water enter a little slower to let heaters warm the water up (assuming you have heaters in the tank).

There was recently a post in the Welcome to Tropical Fish section from someone who had used a python to do a 20% water change with straight cold tap water. Her tap water temp was 45 degrees. She said that it dropped her water temp 10 degrees and she lost fish. While I don't think it should or would drop that much, using 45 degree water to do a 20% WC when the tank water temp was 78 could certainly lower it 5 or 6 degrees. A 25% WC could lower the temp by close to 8 or 9 degrees.

In those cases, I believe you could definitely lower it enough with straight cold water to harm the fish. I doubt that very many people have tap water that cold. I just tested mine and it is about 56 degrees

 

[Tolak]

It also depends on how fast you add the water, and how quickly the tank fills. My tap water is 40F or less in the dead of winter. Most of my tanks are 80F or better. A fast 25% water change will drop it 10F. I've done this with corys, they spawn like crazy after that. Dropping a cichlid tank 10F that quickly results in some of the most sluggish fish I've ever seen. I've tried it with adults, I wouldn't try this with younger fish.

I generally do 50% water changes, and use a mix of hot & cold water. I could trickle it in, and watch the tanks fill all day long. I will do this when I have other tanks to attend to, especially if I want fish in that tank to spawn. Andy is right that if you add it slowly the water heater will heat it to an acceptable temperature. I spent good money for a water heater & by golly I'm going to use it to save time changing water.

 

[rdd1952]

I'm too impatient to add it slowly. Trickling 15 gallon into the 75 gallon and another 5 into the 29 takes too long (and God forbid I do that, forget about it and flood the house). I want to fill them and be done with the WC.

 

[kuhliloacher]

We're just finishing up from a brutally cold winter here in the eastern states, and old man winter isn't quite done with us yet. When I add water to my aquariums, I just use tap water (city water) at 80F. I keep a thermometer in a kitchen drawer next to the sink. I have it down to a science now, figuring out exactly where the knobs on my faucet need to be. Just add some StressCoat or some type of water conditioner, and you're good to go. The thermometer in my tanks never change when I do this, even on a 50% water change. I keep my temps at 78F in my tanks. I would never reccomend adding just hot or cold water to an aquarium.

 

[andywg]

Consider the basic maths (using SI units):

Assume the tank is 24 degrees and the water in the mains is 7 degrees (the coldest possible I am aware of coming through UK mains).

A 20% change will leave you with 80% 24 degree water and 20% 7 degree water. This averages out at 20.6 degrees. That is the absolute lowest the tank could possibly drop to and doesn't allow for the effects of heaters, room temperature, heat generated by pumps and filters or the time taken to fill the tank, this would be a pure dump of 20% of the tank's water straight in instantly.

Most people don't have water anywhere near that cold. I do 40% changes on the 6x2x2 in winter and the temp drops by 2, very occasionally 3 degrees. This is on a tank with no heaters in it (they are hidden in the sump which is off line during water changes) and with the water going into the tank as fast as 12mm garden hose and mains pressure will allow.