Do we underestimate temperature?

[bridgey_c]

I came across a pot of marsilea hirsuta a few weeks back. I have never kept it before so my 'collectoritis' kicked in and I bought it.

I split it into two equal parts and placed half in a discus tank at around 28-29 celcius. Its a 200l tanks with one 30w t8 bulb. I hardly ever dose any nutrients but will chuck the odd bit in when I feel like it or if I see any obvious deficiencies.

The other half went into a high tec 60litre tank, EI dosed, co2 injected, 2x14w t5 bulbs about 10 inches above the water line and kept at 21-22 celsius. Its in a cold room and I can't be bothered keeping it at 25 because im tight and I hate to see the heater constantly on!!

anyways, in which tank was there considerably more growth?

answer : the warmer tank with far less light, no co2, sand substrate and almost no ferts..

I guess there are so many causes and effects happening in a tank that Ive never really been sure of exactly what causes what, but I have just been reading that plant metabolism doubles when temperatures go from 20c to 30c. That is a massive difference! I have always wondered why the stem plants that grow in the discus tank grow like wildfire. When people have co2 issues I never hear about reducing the tank temperature, why not? This obviously massively reduces co2 and nutrient demand.

 

[discusdan]

funny, I was going to make a similar thread.

It makes sense that in warmer temperatures plant metabolism is faster thus the need for more nutrients and carbon but is there a point the temperature is too high and negatively effects the plants?

I normally run my tank around the 26-28 mark but would a reduction in temperature see a boost in plant health due to the lesser need for nutrients/c02 whilst still maintaining the same dosing levels.

I'd probably see a reduction in plant growth but I'd take that over a healthier plant.

Maybe it would be good to see what other people run there tanks temperature at for a comparison?

 

[harryH]

I don't think we 'underestimate temperature' it's just that it's not possible to have the exact temperature for everything in a diverse set up so we have to set an average.

 

[Dan Wiggett]

I was under the impression that most plants prefer slightly cooler temps. I am more than happy to increase so hopefully this thread will get some answers from the 'pros'.

 

[bridgey_c]

I should explain what i meant by 'underestimate' better.

If we assume healthy plants = a healthy tank. We are, in effect, not trying to stop algae directly but trying to grow healthy plants which indirectly inhibits algae growth.

When people have plant problems with co2 deficiency, fert deficiency, excess algae etc, I always hear the usual (and correct) advise of reduce light intensity, reduce photo period, increase co2, increase flow or distribution etc, etc. I never hear to reduce the temp. If we assume a linear relationship between temp and metabolism, a one degree change in temp is a 10% change in plant metabolism. That is huge! I don't know if that basic idea is correct though, just an idea to bounce around.

 

[Michael W]

Hi everyone,

I have asked a question about the relationship between lights and temperatures earlier this year and Clive gives a nice answer about it in this thread Light Vs. Temperature | UK Aquatic Plant Society which may be of interests to yous.

Michael.