Water temp??

[Carper]

Hi all,

I've been trying to research this question but appreciate any views as to the effects this would have on growing various types of orchids.

My collection are mainly multifloral paphs. I use ro water and let the water acclimatise to the greenhouse temp for a few days. However, during winter the water that I am using feels fairly cool. It measures approx. 17C.

The simple questions are;

- Is there an optimum temp for the water that would enable maximum nutrient uptake by the orchid?
- I have been growing a good number of seedlings on a heatmat with vg success & thought water temp would help with the remaining orchids in the greenhouse.

Looking forward to your replies.

Gary
UK

 

[gonewild]

The best temperature for the water is whatever the leaf temperature is.
The easiest way to come close is to have it be room temperature.
For nutrient uptake warmer is better than colder.

 

[consettbay2003]

I use an aquarium heater to keep my water at 72F

 

[Carper]

The best temperature for the water is whatever the leaf temperature is.
The easiest way to come close is to have it be room temperature.
For nutrient uptake warmer is better than colder.

My daytime temp is approx. 20c so would this be the best temp or a little higher. If the plants uptake nutrients better at higher temps, but in the middle of winter, ie short days/low light, would this cause any problems for the plant. I only supplement lighting on the seedlings etc.

Gary

 

[Linus_Cello]

I use an aquarium heater to keep my water at 72F

Same here. My tanks are about 78 or 82 (warmer for discus; Terry Root at a lecture said that he thought the nutrient slime from discus helped his slippers grow better).

 

[phraggy]

I make a fresh mix whenever i water my multiflorals and I won't do it unless the water is warm to the touch. They have strong extra light for 12 hours per day and are showing extra growths on most of them. Repotted a few which are showing new root growth so hopefully I will get some of them in spike early spring.
Never heard the one regarding Discus water slime. I have none now but have bred literally thousands in my tropical years but only raised a number to adulthood -- I can understand that the water will be fine, for the slime is a nutrition for the babies,

Ed

 

[Ray]

I, too, heat my RO tank. I shoot for 75F.

Water in an open tank will never equilibrate with the sir temperature, due to evaporative cooling.

 

[gonewild]

My daytime temp is approx. 20c so would this be the best temp or a little higher. If the plants uptake nutrients better at higher temps, but in the middle of winter, ie short days/low light, would this cause any problems for the plant. I only supplement lighting on the seedlings etc.

Gary

I would go a little higher. But not much more tan a few degrees. I dont think warmer water temperature will cause the plant to uptake minerals faster what it can do is make the uptake more efficient. Leaf temperature and light intensity and root temperature will be the determining factors.

The idea of matching the water temperature to leaf temperature is to avoid cell shock which could cause a delay or shutdown of photosynthesis.

 

[gonewild]

I, too, heat my RO tank. I shoot for 75F.

Water in an open tank will never equilibrate with the sir temperature, due to evaporative cooling.

And leaf temperature will almost always be warmer than air temperature when light is being absorbed.

 

[naoki]

A couple of related thought (not directly addressing the question, but interesting to think about) is the optimum root vs leaf temperature. In many plants, it's been shown that the optimum root temperature is much lower than the leaf temperature. This is related to the reason why diurnal fluctaion in temperature could be beneficial. Both photosynthesis and respiration increases with temperature (within the reasonable range), but the pattern of increase is different (PS rate saturate, but respiration keep increasing). Plants want to maximize the (photosynthesis rate) - (respiration rate) to grow. See Fig 3 of http://www.ext.colostate.edu/mg/gardennotes/141.html

So for non photosynthetic roots (or plants at night) want to have lower temperature to minimize energy loss due to respiration.

Lance, leaf temperature is not necessarily higher than air temperature. Due to the transpiration, leaf temperature could become lower in some situations. Plants do actively control the temperature via stomata control (some people say that plants are limited homeotherms) (related info). While I was learning about Arduino, I saw some indoor growers use the leaf temperature (e.g. with IR sensor) to guide the amount of artificial light (it would be cool to automate this with Arduino).

 

[gonewild]

Lance, leaf temperature is not necessarily higher than air temperature. Due to the transpiration, leaf temperature could become lower in some situations. Plants do actively control the temperature via stomata control (some people say that plants are limited homeotherms) (related info). While I was learning about Arduino, I saw some indoor growers use the leaf temperature (e.g. with IR sensor) to guide the amount of artificial light (it would be cool to automate this with Arduino).

Sure leaf temps can under certain conditions become lower than air temps. But under normal orchid growing conditions indoors under lights or in greenhouse under sun they are generally higher than air temp. :wink:

 

[abax]

I keep the water heater in my greenhouse set on 70F all
year round. My rainwater for Phrags. is normally a few
degrees lower at about 65F. I've been varying the temps.
for Phrags. and Paphs., Phals. for about a year and find
the plants seem to be quite happy with it.

 

[Stone]

In winter (when it's about 8 to 10C outside), 20C water will almost feel hot - certainly warm. On a hot day in summer (like today-about 90C outside), 20C feels cold. Don't go by what the water feels like to mammalian nerves. IMO 20C is a perfect water temp for tropical plants all year.

 

[Carper]

Thanks for all your comments of which I will be applying in my new year trials. I always like to experiment and bring in new ideas for the new year. After a bit more general reading can I also have your views on these 2 please. I normally feed 13-3-15 @ around 400 u/S in RO water. Supplement maxicrop seaweed extract, epsom salts occasionally. PH is around 5.9.

- I was thinking of an application of mono ammonium phosphate.12-61-0. How often would you apply and at what strength. On its own or add to a feed.
- Came across this article and thought it was a joke! What is the advantage and has anyone ever tried it? The addition of alcohol!!!!!

http://www.staugorchidsociety.org/PDF/OrchidWANTSbyWeymanBussey.pdf

Gary
UK

 

[gonewild]

On a hot day in summer (like today-about 90C outside), .

Where do you live anyway? Hell?

 

[gonewild]

- I was thinking of an application of mono ammonium phosphate.12-61-0. How often would you apply and at what strength. On its own or add to a feed.

What is the purpose?

 

[consettbay2003]

Thanks for all your comments of which I will be applying in my new year trials. I always like to experiment and bring in new ideas for the new year. After a bit more general reading can I also have your views on these 2 please. I normally feed 13-3-15 @ around 400 u/S in RO water. Supplement maxicrop seaweed extract, epsom salts occasionally. PH is around 5.9.

- I was thinking of an application of mono ammonium phosphate.12-61-0. How often would you apply and at what strength. On its own or add to a feed.
- Came across this article and thought it was a joke! What is the advantage and has anyone ever tried it? The addition of alcohol!!!!!

http://www.staugorchidsociety.org/PDF/OrchidWANTSbyWeymanBussey.pdf

Gary
UK

What is the source of nitrogen in your 13 -3-15?

 

[Ozpaph]

Where do you live anyway? Hell?

But its heaven when its low 80s! (for weeks on end, at least up in Brisbane).

My orchids get ground temp water 365/7. In winter that's probably in the low 60sF; though heated glasshouses are uncommon in this part of the world.

 

[gonewild]

But its heaven when its low 80s! (for weeks on end, at least up in Brisbane).

90c ?.
I'm assuming it does not reach 90c on the surface even in Australia. oke:

 

[Carper]

What is the purpose?

Lance,

Just reading through various comments and threads that some growers get better growth through urea based nitrogen. Thought that feeding alternately might be worth a go.

Live in Nottingham in the UK. Getting milder, wetter, fair winters but poor summers!!! We're in the middle of winter, had no snow yet, don't think a frost, and temps outside have been 15-17C. Still very short days, just lengthening form about 7 hrs of very poor light for the next 3-4 months.

Gary