Consistent temperature's... really???

[Magnum Man]

I've seen some people with multiple heaters & various ways of trying to make their whole tank exactly the same temp all over... ( in all fairness I put my heater in the filter discharge flow... so I must be trying as well ) but in nature the fish swim around through varying temps all the time... shady areas, are cooler there is often huge temp changes with depth ( I scuba dive, & there is often a 10 degree temp change in 10ft... is it really important to try to make the whole aquarium exactly the same temperature??? or is that just the perfectionist in us??? I can't imagine that if your heater was on one side of a 55 gallon, even if it's not in an area of water movement, that the other side of the tank would be more than 1-2 degrees colder

 

[Fishies4Ever]

Never really thought that it might be warmer or colder in some parts of our tanks. Like you were saying in the wild there are colder and warmer spots so it seems natural, and with the circulation from the filter the warm water moves through the rest of the tank probably making It the same temperature? I’m not to worried about it because it happens in the wild and our tanks, although we don’t want to admit it can’t be perfect.

 

[Mikeyboy123]

You are right, there will be eddies and currents in water bodies, as well as locations where different tributaries are coming together, so a bit of natural fluctuation does occur. It's not something that I think about. If my thermometer is telling me it's X then I'm happy, and whilst the other side of the tank may be a little cooler i don't think it's of much concern. Some fish may be more sensitive than others and i suppose it's something to bear in mind at water change time, but i don't think it's that much of an issue really as long as you are there or thereabouts.

 

[10 Tanks]

Hello. If you choose to heat your tank, putting a heater on either side of the tank and setting an air stone attached to an air pump in the middle of the heaters will distribute the heat more efficiently. I keep my place warm enough that I don't need to heat my tanks and keep fish that like their water a bit on the cool side. The temperature of the house stays at 77 degrees in the Summer and 72 in the Winter. So, the water is is consistent throughout the tank.

10 Tanks (Now 11)

 

[Byron]

There are two distinct but closely related factors here. The temperature in the habitat waters (nature) and the temperature variations in the aquarium.

Taking the latter first, in especially larger tanks the water will always be cooler above the substrate than it will near the surface. This mimics habitat waters, but in the aquarium the water is drawn down through the substrate where the decomposition process warms it, and the warmer water then rises back up into the aquarium. I don't have numbers, but this is a fairly slow process. The water near the substrate will be cooler. In my 70g, 90g and 115g tanks this was quite noticeable when I had my hand down at the substrate rearranging plants or whatever. People suggest having internal heaters horizontal and close to the substrate so the water is warmed and naturally rises. Having the filter return very close to the heater is always advisable so the warmed water circulates. It also saves the heater...the constantly warm water around the heater will cause it to go off more, and on and off more, which wears it out faster.

A diurnal variation is sometimes suggested, achieved by two sets of heaters set at slightly different temperatures and on timers so the warmer ones are on during the day and the lower temperature heaters during darkness. We had some threads on this a couple of years back. I don't hear much about this any more, but if not taken to extreme it should be practical.

Which brings me to habitat water temperature. In tropical watercourses, the variation between day and night water temperatures is no where near what some may assume. A couple degrees, sometimes not even that. It depends upon the circumstances. Water retains heat longer than air. And the forest floor retains heat too. These together result in minimal if any temperature fluctuation diurnally. And season variation is almost non-existent. The rainy season will bring cooler water, sometimes and maybe. The air is very warm above the organic forest floor, and the heat will affect falling rainwater.

In their data on the habitat of Mikrogeophagus ramirezi, Linke & Staeck (1994) noted that on an overcast day, at 10 am in the morning, the water was 28.5 C (83F) and the air was still "relatively cool" at 31C (88F).

 

[emeraldking]

Well, my view on this is that fish that we keep in aquariums can exposed to temperature fluctuations. But in a smaller and closed environment indoors, it's better to keep the temperature fluctuations to a narrow margin. When this is done outdoors, the margin can be higher. But again, indoors it can influence the fish more than outdoors. In natural water in free nature, the margin of temperature fluctuation throughout the day is higher but depending on the the water body, fish can dive deeper if it may influence them too much. But it also depends on the kind of fish if temperature fluctuations is bothering them or not. So, there's no real answer to this unless you know of what kind of fish we are talking about.

I myself do expose most fish I keep to a bit lower temperature levels as they usually would need. But they get used to it from a younger age. This does make them stronger is my own experience. And those who have got fish from me can relate to that they're stronger than the same kind of fish which are kept at a steady temperature.