Temp Match Partial Water Change

Here in Florida, groundwater temperature in the winter is about 68 degrees. By the time it gets to the tap I use to fill the aquarium, it is closer to 70 degrees. Maybe 71 or 72 by the time it gets to the end of my 50 foot Python.

I keep my tanks about 78 degrees. So if I do a 50% water change without temp matching the water, the temp would drop to 74 or 75 degrees. If I fill slowly and direct the new water on the water heater, maybe the drop is only to 75 or 76.

I am thinking for Guppies, that is okay. Agree?

The reason I want to do this is that I am bypassing a water softener when I fill. But if I use the water heater to temp match, I would be mixing in a bit of softened water. Not a big deal, but I like the idea of pure non-softened water and I like the idea of not getting any non-softened water into the water heater. And honestly, it is easier not to mess with temp matching the water.

I am thinking that Guppies are pretty hardy so a drop of 2 to 4 degrees while doing a water change should be no big deal.

I also have Guppy fry that would be subject to the same water change. I wonder if fry would be more sensitive to temperature fluctuations? Intuitively I would say yes. However in another thread emeraldking stated that Guppy fry are actually very tolerant of low temperatures. Would that also extend to tolerance of temperature fluctuations?

I also have a Betta. Similarly tolerant?

Would it make any sense to keep the aquariums closer to 75 degrees in the winter so that the temperature difference would be less?

 

Don't stress too much about a few degrees gain or loss during a WC unless you are a commercial breeder. I wouldn't lower the temp of the tank either to match the season.
I've been making 50% weekly WC's in my tanks for more years than I care to mention, Lol. I use the finger dip in the bucket test trying to match temps. I try to have the replacement water just a tad warmer. Never a bad reaction due to a moderate temp fluxuations.

 

Cool water will often induce breeding as it emulates the flood season for many fish .
You're all good with a couple degrees IMO for both adults and fry .
Many breeders offer water cooler to induce spawning [a big trick for cories ] .
With other more difficult to breed fish it is called the dry season/ flood season method where you reduce water changes and raise temp for a couple weeks then flood the tank with cooler cleaner water to induce breeding ..
No worries with your IMO but I bet the betta would like it all warmer !

 

I bet the betta would like it all warmer !

Would the Betta also be less tolerant of temperature variation in water changes? It would not be too tough to temp match the water change on just that ten gallon tank.

 

Would the Betta also be less tolerant of temperature variation in water changes? It would not be too tough to temp match the water change on just that ten gallon tank.

Again I wouldn't worry about it, from my experience temperature shock is caused by a big difference in temperature and very sudden.
A point on the Guppies, I actually raised one from fry in about 64-68f for about 4 months.

 

I am sure the betta is tolerant but compared to guppies they like warmer softer water is all I was getting to ?
It is always best to offer what you have so don't do crazy stuff just for the betta but take his preferences into consideration if note any type of reactions during water changes .

 

A point on the Guppies, I actually raised one from fry in about 64-68f for about 4 months.

Same here