# The Effects of Temperature on Growth



## AaronT (Apr 26, 2004)

I read a fair amount of posts from people wondering how come they are not getting good plant growth. It is usually followed up by someone responding ask for tank parameters, but nine times out of ten those parameters never include the temperature of the water.

It was suggested to me a good while ago, I believe from SCMurphy, that planted tanks like lower temperatures than conventional aquarium thought would have us believe is necessary to keep the "tropical" fish that we do. I have since started running my tanks heaterless in the summertime and keep them in the low 70's during the winter. Growth has improved and the fish are as happy as ever.

Is anyone else experimenting with water temperatures to achieve better plant growth? If so, why do you think that is?


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## SnakeIce (May 9, 2005)

optimum temperature range really varies from plant to plant. Kasselmann's book Aquarium plants has an index that lists such for some plants. Crypts tend to be in 22-26C range with some a little higher and some a little lower. Elodea canadensis 15-20C

There are exceptions, but based on optimum ranges listed, some where between 23-25C hits a lot of plants good range. With equipment heating things up during the day it would be better to start out a little low, say 72*F.


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## turtlehead (Nov 27, 2004)

I have my plants growing in temperatures lower than the 70s, I think it's better than the heat.


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## Cavan Allen (Jul 22, 2004)

I think that along with good water movement, temperature is one of the most overlooked factors affecting plant growth. While emersed, plants can cool off through evaporation, but while submersed, the obviously can't. That's why the same plant that grows emersed along the edge of a pond during 90 degree summer heat in someplace like Minnesota may not be able to handle water 10 or so degrees colder in our tanks. Some plants from temperate latitudes can adapt, and some can't. I don't really know why.

I can say that there a good many plants that will grow quite a bit larger and healthier when temperatures are lower. As I've said before, _Hottonia palustris_ is a LOT more impressive when everything else being equal, the temperature is lower. It will survive and grow in warm water, but doesn't even come close to reaching its full potential.

Lastly, although the air temperatures in a lot of places may be fairly high, the water temperature isn't necessarily as high.


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## plantbrain (Jan 23, 2004)

Like light, the more energy you add, the faster the growth rates will be(up to a max then enzymes start breaking down slowing growth), algae are also responsive(can bloom) to temp changes.

Each plant species has it's own temp specific enzyme, Hydrilla can be grown at 10C easily as well as 40C.

Colder water holds more dissolved gas also.
The growth rate is slowed down and the assimilation is better organized within the plant(the same is true when using less light, which will also lower the temps in the tank FYI).

I think tanks tend to be more squirrley at higher temps, mainly algae+ response to CO2 and nutrient dosing.

I'd pick 72-75F if I had a choice.

Regards, 
Tom Barr


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## Cavan Allen (Jul 22, 2004)

> The growth rate is slowed down and the assimilation is better organized within the plant(the same is true when using less light, which will also lower the temps in the tank FYI).


Not to hijack the subject of the thread, but I've noticed that when it's really growing fast, java fern can look very pale or even yellow towards the ends of its leaves even though there is certainly enough iron in the system. That might be a good example of plants growing a little too fast for their own good.


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## Happy Camper (Jul 22, 2004)

Cavan Allen said:


> Not to hijack the subject of the thread, but I've noticed that when it's really growing fast, java fern can look very pale or even yellow towards the ends of its leaves even though there is certainly enough iron in the system. That might be a good example of plants growing a little too fast for their own good.


Hi Cavan 

I have Java Fern growing in my Tanganyika tank. This tank gets dim light for about 4 hours each night, no ferts added at all, I also see the same thing with the Java Fern, it's not from very fast growth. JFYI.


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## urville (Sep 20, 2004)

you also have to consider that 50 degrees f isnt really the same thing at higher altitudes that it is at sea level for instance. i mean 50 is 50, but the feel is different. i've been to the west coast at 50, and then gone back to Wyo and 50 here is just much colder feeling here.
so...
thats how things like boston ivy an evergreen ivy can survive the cold winters there but not here. temps get down tot he same levels, it's all about altitude.


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