Does anyone adjust tank temperature to mimic seasonal changes.

[jaylach]

Came across a couple of articles about this and the topic seems mixed as to yes or no. Of course this can be needed for breeding but I'm talking about seasonal adjustments just to mimic nature. I doubt that I would do it, just leaving things consistent, but it seems an intriguing concept.

I'd just be interested in other's thoughts on this. I DO understand that, besides guppies which I still think are born pregnant, it can be needed for breeding but I'm interested in possible pros and cons without breeding being a factor. One issue I could see is doing seasonal temperature changes could actually promote breeding when it isn't wanted.

 

[GaryE]

As always in our hobby, the devil's in the details.

You can manipulate the temperatures for fish who experience seasons. For some fish, adjusting to seasonal swings when they don't come from a habitat with seasons other than rainy or dry is harmful. If you have a fish from either south or north of the year round temperature stability zones, manipulating the warmth of the tank is a legit approach.

A change of 2 degrees celsius can disrupt the digestive enzymes of some equatorial species, while doing nothing to others. It is really hard to get good info on water temperature movement for a lot of our fish, plus we have a hobby pattern of keeping our fish warmer than they'd be in nature.

The famous example is the Corydoras and Danio experience, where sudden drops in temperature trigger a rainy season response with egg laying.

 

[gwand]

I don’t know about my fish but I like a constant balmy 74F, low humidity and no rainy season. In my youth I did my best breeding under those conditions.

 

[seangee]

Not intentionally - but in summer, with heaters turned off, my tanks are warmer than winter. Some years the difference is quite significant.

 

[Colin_T]

I didn't change the temperature of my heaters but I did have them set on 18-22C depending on what fish were in the tank. As the weather cooled the water temperature dropped to 18-22C and sat there over winter. As the weather warmed up in spring and summer, the water temp went up too. In summer the water sat on around 30C (86F) and dropped to 18-22C (64-72F) over winter.

I had a lot of rainbowfish from Australia and New Guinea, and native fishes from the south-west of Western Australia and they all experience temperature fluctuations during the year. In the south-west of WA the water temperature can fluctuate 30C (from 5-35C) during the year, whereas in the north of the country it might only vary 10-20C during the year. I also had barbs, cichlids, catfish and tetras. Some of the fish like barbs and natives from the south-west didn't have heaters and the water would drop to 15-16C over winter (sometimes lower than that). When spring hit and the water got to 18C the fish started breeding.

When keeping fish at lower temperatures you can reduce the feeding and monitor fish for fungal infections. I had a number of bottom dwelling fishes (Galaxias occidentalis, G. truttaceus and Bostockia porosa) from the south-west that would get covered in fungus and stick to the bottom of the tank. I don't know why it happened but it did every year.

In the wild fish will be exposed to varying water temperatures with warmer water found near the surface and cooler water at the bottom of the river, creek or lake. This is more for stationary waterways and less in fast moving water. I tested temperatures in pools and waterways in the south-west of WA and there could be a 10-15C difference between the surface and bottom. I was in a pool on a golf course down in Walpole (Western Australia) and there were baby salamanderfish (Lepidogalaxias salamandroides) in the shallows. The water temperature was 30C in the shallows (1-2 inches of water around the edge of the pool). I tested the temperature at the bottom of the pool (it was about 4 foot deep) and the temperature was 15C. The adult salamanderfish were found on the bottom while the babies were at the top in the warm water. The warm water helps speed up their metabolism so they grow faster and there is more food in the warmer shallower water, which also gets more light to encourage single celled algae.

I tested smaller pools of water in different areas down that way and some were only a few inches deep and the water temperature was around 35C during summer. Some of the smaller pools had no fish (they appear to have been fished out by birds, there were bird footprints by the pools) while others had a variety of juvenile and adult fishes in them.

I tested moving water (creeks and streams) as well. Some were fast moving while most had a moderate or slow flow. The water temperature in these flowing creeks was noticeably cooler than the stationary pools and most of the moving water had temperatures in the low to mid 20s Celsius during summer and 5-10C in winter. The stationary pools and flowing creeks contained the same species of fish and all the areas tested were within a 50km radius. So even in the wild in the same location, there are temperature fluctuations in the water temperature and the fish are exposed to these fluctuations throughout the year.

 

[jaylach]

One thing I neglected to mention in my initial post is the difference between wild caught and tank bred fish. I would think that temperature changes for wild caught would likely be better than tank bred fish.

 

[GaryE]

One thing I neglected to mention in my initial post is the difference between wild caught and tank bred fish. I would think that temperature changes for wild caught would likely be better than tank bred fish.

I don't think this would matter. Things like temperature needs run deep in the DNA, and a few dozen captive generations aren't likely to change that. Again, the whole question relates to where the fish are from. If your fish evolved in a region with seasonal changes, then seasonal changes can be a good idea. If they didn't, then subjecting them to fake seasons would be a stress.

In many ways, a lot of us are forced by our own environments to short change some fish. If we live in temperate zones with seasons, unless we're into sealed, climate controlled housing, temps are going to fluctuate and get beyond the temperature comfort range of a lot of fish. We can control the lower range with heaters, but without AC, the summer with what are increasing temperatures is a tough time for fish.

I think the view that captive fish adapt to aquarium conditions is a myth that comforts us. Those are the most popular myths, and they stick around with no evidence to support them. It looks to me that some fish are tougher than others and more able to take abuse, and we pretend that means they've adapted to inappropriate aquarium conditions.

I think one of the things we should do when we think about these issues is to lose the word "fish", and come back with with a clearer focus on which fish species we're talking about. Even with the relatively few species available to aquarists (compared to the many more in nature), the differences in what they need can be enormous.

 

[Itsadeepbluesea]

I do not intentionally adjust my temps, but in the summer the house is a bit warmer and the heater generally does not need to kick on. Due to the ambient temps the take does get a bit warmer.

 

[anewbie]

i do to a degree. Sometime because the fish i have require it and more often because the room with the aquarium gets warmer during the summer than the target temperature.

There are some fishes that actually require a temperature change to maintain optimal health and others who will die - so you gotta know your species. Of course with a ton of species no real information is known or readily available about their native habitat.

 

[emeraldking]

Does anyone adjust tank temperature to mimic seasonal changes.​

Well, with my goodeids I do adjust the temperature. For they need a period of cooler water then they were already in... This is to give them a period of rest. which is needed for a large number of goodeid species.

 

[GaryE]

I don't imagine (maybe hope) that not too many "into it" aquarists don't check where there fish originate using something like fishbase.org, and then google earth. If they cluster around the equator, then temperature stability is in order. As you move away north and south, things get closer to temperate and you begin to have seasons the way Europeans and North Americans envisage them.
Seasons to central Africans are rainy and dry with temps usually around 26c year round. In my habitat, we can range from 30c to minus 30c. A lot of people tend to think that where they are is how the world works. We're affected by changes in sunlight - I hate watching the night starting earlier and earlier every week now as we slide down. Some of our fish are tuned to the same rhythms, but a lot have 12 hours of light, always.
My rainbowfish used to get artificial seasons when I was really into them - a breeding season and a keeping season. Why? Because fish tuberculosis develops more slowly in cooler temps, but they needed a warm period to breed. Since the group is prone to tb (why I gave up on them), that was a working strategy.
When I had Goodeids, they got seasons. They did far better with them. Generally fish from Florida and Mexico had a cooler period worked in. I once left Montreal at around 6c and arrived in Miami at 1c, somehow managing to head south to the cold. They get seasons, and that's good for fish from there.
Now, I have softwater and temperature stability in my set up. So I've changed my ways and now have only species from the stable, equatorial zones of Africa and South America. If I wanted them, there are also many Asian species that would thrive in my one season forever set up. I may have at most a one of two degree variance in seasons, and this month I decided to officially give up on trying to modify that and just roll with what the fishroom set up gives me.
We lazily generalize and say we keep tropical fish, but there are a lot of sub-tropical and even temperate fish in the hobby. They don't tell us who they are, but we can check that out easily.

 

[GaryE]

https://journals.biologists.com/jeb/article/228/18/jeb251604/369277/Fluctuating-temperature-has-unexpected-impact-on

This is interesting. Fundulus heteroclitus can be found close by my Canadian house, where they would never encounter the warm temperatures researchers used in these experiments. However, nearby populations in shallow ponds would get up to 26 for a few weeks in high summer, so the plot thickens here.

 

[Rusty_Shackleford]

Yes, I do this. But not for every species. I wouldn't vary the temperature for a Lake Tanganyika tank, but I would for Gymnogeophagus species. Research is key, for any animal your considering.
Researching climate data has become pretty stndard for reptile and other exotics keepers. I loved doing the work. I remember researching some dart frogs from Panama and was surprised that maximum day length in summer was 12 hours and in the winter it was 11 hours. Almost no change.
This is the reason we have the interwebs and though you still have to work to find. There are sites for climate as well as day/night length etc.
Light is a tough one to manipulate as many of us keep live plants as well, and we don't want to encourage algae by changing light schedules.
Temperature is certainly something we can change and observe the changes in our charges. Why aren't more keepers doing it? Is nature ever static? Even in equatorial Brazil there is some change in temperature. The rainy season brings more clouds and less direct sunlight. Rainwater will cool lakes, ponds, and rivers to a lesser extent. I would live to see more research done as far as in situ temperature with species that are currently in the hobby.
It seems farily simple and cheap to create a solar powered device to leave in place for years and have it send data once a day to a satellite.

 

[Colin_T]

The temperature and water chemistry in Lake Tanganyika varies throughout the year. In the dry season water evaporates from the lake and the temperature, pH and GH go up. In the wet season the temperature drops a few degrees and the pH and GH go down.

In lakes that don't have lots of limestone rocks in, the pH can go down during the dry season and up during the wet season. The GH can go up during the dry season and down in the wet season. And the temperature goes up in the dry and down in the wet.

 

[GaryE]

Researching climate data has become pretty stndard for reptile and other exotics keepers. I loved doing the work. I remember researching some dart frogs from Panama and was surprised that maximum day length in summer was 12 hours and in the winter it was 11 hours. Almost no change.
This is the reason we have the interwebs and though you still have to work to find. There are sites for climate as well as day/night length etc.

When you are new to the hobby, you tend to keep the same bread and butter fish as other newcomers. The industry sets your choices for you, and if you only have chain stores, your choices are severely limited. Chances are, you won't be into breeding fish, and want a pleasant spectacle. They used to sell aquarium thermometers with a section marked as ideal for fish, and you can stick to that 23-26 range.

It's only really the aquarists who frequent forums or fish discussion or who branch out to explore who care about trying to mimic nature. I'd love to see the pendulum swing back to there being more and more of us. If breeding rather than consuming becomes popular again, we can do it so much better than the last period when learning about nature via aquariums was fashionable. Back then, we shared info with aquarists we met, picked the brains of people who had been to fish habitats and found things here and there in print. We can access so much more info (though as @Rusty_Shackleford notes, it takes work. Work is the basis of learning). There is climate research galore, and a much better possibility for networking. I suspect as AI expands and corporatises, we'll need to learn better research techniques as the kind of info we want will get pushed down deep by the algorithms of conformity we're dealing with. But we can adapt and dig, even if we aren't in the scientific loop. AI already wants to summarize my searches, and isn't designed to offer me details.

It's all about diversity. It's a simple idea that hasn't caught on in our hobby. Things are different from other things. Fish are different from other fish, and 'general' rules on keeping them are weak.