Do you equalise water changes with the main tank's temperature ?

[Warr7207]

I would like to know if who actually make sure there WC water is the same temp. as the tank ?

[Mekaeel]

in my case when i use synthetic.i keep the RO drum in the sun to heat up to 26 then add the water to a drum,chuck in salt until i get a SG 1.026

[Tobes]

I first heat the RO up to 25deg and then add my salt - dissolves easier when water is warmer. I then leave the heater and powerhead inside the drum until I do a water change. I match the temp and salinity(using a refractometer) as close as possible to make my fishies feel comfortable in their glass home

[Mike]

Yep, i have to, otherwise you can't get the salt through the ice.

[gaz19]

oooops

[Rory]

You should heat the water up any way to aid dissolution. I'd imagine it would also be better to oxygenate it at the temp it will be at in the tank

[Al]

Did my first water change on Saturday, Heated my water from Friday night and added salt after the water was about 20 -22deg.Left it for the night and did the water change on saturday.
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[Mekaeel]

make sure the temperature of the new water is the same as your tank.too cold water will result in a whitespot breakout in fish

[Warr7207]

The reason I asked this question is if you do the sums, the difference in temperatures has to be huge or the WC huge (%wise) to actually effect the tank.

I take Rory's point that warmer water may dissolve the salt quicker


Temp. Sum:

50L @ 20°C is mixed with 450L @ 25°C, the 50L is 10% of the total volume (50 +450), so it's temperature effect will also be 10% iE: -0.5°C (10% of 5°C)

I know there maybe other factors involved with water temperature.

If I am calculating this right a normal type WC for me 5%, would need to be over 20°C difference, before I would have a significant temp. swing.

My 2c

[Quinton]

I don't fuss as much for smaller changes (say 5-10%, although the solubility points above definitely do apply). But for larger changes (e.g. 50%) one needs to be very careful to match the temp, salinity and pH.

[Rock pool]

When I collect from the sea I just leave the drums in the sun for a few hours

[Rory]

While it's true a smaller water change wont have much effect on the temp a .5 degree swing in a few seconds is probably pretty big to some sps... If I know the water is a very different temp I will add it bit by bit.

[Alan]

Depends on the size water change, for std water change of 150L then no i dont, as its only 5% of system. Larger water changes of 40 - 50% i would.

[Mekaeel]

very true,i would think any water change less than 10 % wouldnt really affect the tank temperature

[Mekaeel]

by the way,make sure that 10% isnt an ice block

[CaCO3]

For smaller changes I have 2 drums of same size +-20l. First I make sure the level is correct (top up.) The next day I syphon from the tank into the one drum using air hose, at the same time I syphon new water from the other drum also using air hose. Takes about 30 minutes or so.
It is gradual and I can chill with the rugby and a at the same time.

[Len]

I buy pre mix in a 20 l container. Before a water change I leave a heater (set at my tank temperature) and a air stone in it for 48h.

Important to check the salinity again as I have notice serious differences between the different shop's mix strength.

[Matt]

I voted no but I do heat my water - to approximately same temp as tank - I find the water change as negligible effects on temp if it's not exactly the same temp.