Cold water into tank on water change problem

[martin_jones]

I have just done a 40-50% water change on my 75G as I am doing EI dosing.

I then noticed a number of my fish (1 cockatoo, 1 blue ram, 1 otto and 2 cardinals) all lying on the bottom of the tank looking dead.

I immediately got them out and into a net on the surface where they appear to have come back to life.

I can only think that the water change lowered the temperature too much (it was reading 16C) so have put some hot water in to raise the temperature (it's around 19 now and the fish seem ok).

My question is how do people do water changes using a python? Obviously too much cold water isn't good for the fish. Should the python be used in the winter?

I am on a well (not city water) so I guess the cold weather affects the water temperature.

Any thoughts?

Martin

[KLKelly]

Why can't you use warm water on a well?  I'm on a well also - but don't you just check the temperature via the tap and then fill up the tank with the python?

Also a note with my well:
PH out of the tap is 7.6.  PH after bubbling in a bin because my well is high in CO2 is 9.0.
If your well water is like this a large water change could cause PH shock could also cause them to be unwell.  You don't want ph to change quickly.  And of course the temperature difference for sure.

[Nerine]

You MUST have warm water that comes out of the tap

I never put cold water in the tank unless it's a cold water tank, otherwise you're just asking for troubles!! think of how we feel plunging into the ice

Just make sure the water is close to the tank temp

[celamllmal]

I personally do not know about wells but know that if I don't replenish my tank with water that is close to the same temperature as what what taken out that my fish act differently.  I have Malawis and Tangs.  I always try my best to match the water temperateure as best as possible.

[dan2x38]

I use a python I set the water to 75d then fill. Add a small bucket at the same time with the total dose of ChoramX for the tank as it fills. With SA fish KLKelly is also making a key point about the pH. All of the fish you mentioned are sensitive fish to change of most any kind.