How to replace water with same temp.

[venymae]

So I've read a lot that when replacing water, it should be the same temperature to reduce shock to your fish. How do you get the water to the same temperature? Do you guesstimate or do you actually stick a thermometer in and keep fiddling with it until it's right? I only have one heater, so I can't use one to heat the water about to be put in (not to mention my toddler would proooobably spill the water in the time it took -lol)
So, how do you work this out in your house??

 

[gilpi]

So I've read a lot that when replacing water, it should be the same temperature to reduce shock to your fish. How do you get the water to the same temperature? Do you guesstimate or do you actually stick a thermometer in and keep fiddling with it until it's right? I only have one heater, so I can't use one to heat the water about to be put in (not to mention my toddler would proooobably spill the water in the time it took -lol)
So, how do you work this out in your house??

Most likely you're replacing around a quarter of the tank's water more or less? I guesstimate by touch, unless you were replacing something like 75% of the water, then you should be closer to the same temp as your tank.

 

[Brookster123]

I fill up buckets and float a thermometer, I know it may not be practical for larger tanks, surprisingly your hand (barring any neurological conditions) can differentiate between temperatures quite well. Just dip your hand in the tank and than under the faucet/bucket.

 

[Mebbid]

If im not mistaken the hand can detect a 2 degree temperature change. I usually just check temp with my hand when doing a 50% water change. Even if the temp is off by 4 degrees, it will only change in the tank by 2 degrees which fish really don't care about.

 

[DragonFish71]

I do it by feel. I know what my tank water feels like to my skin, I know what the water coming from my faucet feels like.

I also fill some of my tanks with cooler water to induce spawning.

 

[tnfinfan]

Digital meat thermometer. Works great!

 

[apr28]

I do it by feel. I know what my tank water feels like to my skin, I know what the water coming from my faucet feels like.

I also fill some of my tanks with cooler water to induce spawning.

I do it by hand also. Fish are frisky after change so something must be right.

 

[Candi1990]

I feel horrible listening to you guys i guesstimate and use tap water. And i know most times its not close to the same. I know not to put HOT water in, or cold water. I make sure its room temp ,aybe a little warmer and never had a problem. I have too many tanks to use buckets and thermometers although i think its great if you can do that.

Doing a 50% change i dont think it matters much unless you have a tiny tank or really sensitive fish.

 

[enrgizerbunny]

I let my water sit and rose tip room temp, 72 degrees, I have a crappy heater I toss in the 10g I use for water so that 40% of my change water is only 3 degrees off, the rest is 6, tank temp rides right at 78. Did my water change tonight, temp only dropped 3 deg, which I countered with 3 hot cups slowly poured in to raise 1 degrees and top off the tank to full. Works pretty well.

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[enrgizerbunny]

Also, I have a digital thermometer with a probe to check between the bucket and tank.

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[Ian086]

I use my hand too. If you have a digital option on your water boiler, set it to heat the water to the temp of your tank....

 

[illuzion7]

I also use a meat thermometer..works great, and saves time for bigger tanks.

 

[T1KARMANN]

The water doesn't need to be the same temp

When I had my 350g I drained 25-30% of the tank
Dosed the full tank volume with seachem prime them filled back up from the cold tap
I used to get a temp drop from 86 down to 78 in winter with no problems at all

In fact the fish loved the temp drop as it simulates rain fall

The temp wouldn't be constant in the wild it would drop at different times of the year it will drop over night when it rains or even at different water levels depending on water depth

Never had a problem

 

[Ian086]

The water doesn't need to be the same temp

When I had my 350g I drained 25-30% of the tank
Dosed the full tank volume with seachem prime them filled back up from the cold tap
I used to get a temp drop from 86 down to 78 in winter with no problems at all

In fact the fish loved the temp drop as it simulates rain fall

The temp wouldn't be constant in the wild it would drop at different times of the year it will drop over night when it rains or even at different water levels depending on water depth

Never had a problem

Great point!!!

 

[Fidgetromeo]

I fill buckets from hot and cold tap and guess at what feels about right, never caused any issues, and as said above temperature changes in the wild by a few degrees anyways

 

[ScotJudd]

I also use the finger dip test. Occasionally I use a thermometer to check but found I am rarely more than a couple of degrees out.

 

[T1KARMANN]

I fill buckets from hot and cold tap and guess at what feels about right, never caused any issues, and as said above temperature changes in the wild by a few degrees anyways

It's not a good idea to use hot water from the tap as the boiler and hot water tank are full of rubbish

I wouldn't drink water from the hot tap would you

 

[enrgizerbunny]

It's not a good idea to use hot water from the tap as the boiler and hot water tank are full of rubbish

I wouldn't drink water from the hot tap would you

Not to mention most hot water has lead in it, that's why you don't use hot tap water to make baby formula.

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[mataichi]

I use a digital cooking thermometer. For my big tank I fill buckets with 3 gallons of cold water and then add a gallon of hot and it's usually witin a few degrees of the tank. If it's off I let it sit for several hours, my big tank is a goldfish tank and is usually at or just above room temp. For my small tank I turn the water on in the sink and put the end of the thermometer in the water flow and adjust it there. Once it's right I fill up gallon jugs.