Constant temperature/ variable temperature

[chris1805]

HI guys,

I was thinking about the following idea. As most of us have experienced that when we do a waterchange, we get increased spawning activity of our Apisto's. This could either be because they finally get some decent water, although i am quite sure we all maintain our tanks the best we can. Ofcourse a waterchange serves as a primary purpose of removing excess nutritions. However it also impacts the temperature in our fish tanks, unless you heat your water before you waterchange it to the exact temperature. This would indicate that our fish do react at temperature differences.
Now in the wild temperatures at night fall down quite a lot compared to the temperatures during the day when the sun is shining on the water. I was therefore thinking, would it be a good idea to try and simulate this by putting a time-clock on the heater? Atleast inside my house temperature does not get below 20 degrees celcius, my fish tanks are at about a 24-25 degrees celcius. So i was thinking about turning the heater of at night, so that temperature drops a bit over night, and turn the heater back on as soon as the led lights starts to rise. Do you guys think this will give some added value or am i overthinking things?

Kind regards,
Christian

 

[gerald]

Fish that live in shallow lakes and ponds probably experience daily temperature cycles like you describe, but most Apistos (far as I know) live in streams in forested areas where there's not likely to be much (if any) daily cycle in water temperature. Rainfall and seasons will certainly change the temperatures, but not on a daily cycle of course.

 

[chris1805]

That’s also a true thing.. have you any experience with this?

 

[gerald]

I have never been to S. America, but I've seen that phenomenon many times in local swamps and ponds. In Feb-Mar many fish will move into sunny spots in shallow water, especially among leaf litter and plant beds, to get a bit of solar heating.

 

[Mike Wise]

My experiences in the Amazon, three 4-week expeditions thanks to encouragement by TomC, is that the same thing Gerald describes occurs there. Dr. Römer wrote an article about how apisto females select breeding sites in the wild. The dominant females select the ideal temperature zones and drive out the other females, who breed in warmer and cooler zones. The dominant females produce 50/50 sex ratios while the less dominant in warmer water produce more males and those in cooler zones produce more females. The end result is about 50/50 overall. My experience with stream temperatures is that they are relatively stable - at the same depth - over the 24 hours in a day. Most noticeable temperature fluctuations are due to heavy rains that cool the water.

 

[chris1805]

My experiences in the Amazon, three 4-week expeditions thanks to encouragement by TomC, is that the same thing Gerald describes occurs there. Dr. Römer wrote an article about how apisto females select breeding sites in the wild. The dominant females select the ideal temperature zones and drive out the other females, who breed in warmer and cooler zones. The dominant females produce 50/50 sex ratios while the less dominant in warmer water produce more males and those in cooler zones produce more females. The end result is about 50/50 overall. My experience with stream temperatures is that they are relatively stable - at the same depth - over the 24 hours in a day. Most noticeable temperature fluctuations are due to heavy rains that cool the water.

That is some great information Mike I think i can conclude on this that it is best to keep the temperature constant.