Achieving Day/Night Temperature Differential for Indoor Setups

[JKeys]

Hi all!

This question has been on my mind recently, as I consider moving my plants to school with me. I have a somewhat haphazard indoor setup. Plants live in a 40 gallon topless tank, exposed to light from a single window (I thought the tank would help with the humidity -- it's really dry in these rooms!!). I'm thinking about bringing my grow light in, it is a reflective fixture with two t5 bulbs. In any case, I know many of the orchids I am growing would do well to have a few degrees C of temperature difference day to night... At this point, I am not sure if the ambient temperature of the room really fluctuates that much. I'd be interested to hear any strategies you have of achieving this, grow lights or not.

Thanks and happy growing!

[Ray]

You'll want to verify, but I suspect that the temperature in the tank with lights on versus off will be quite different, especially if you partially enclose the top to trap humidity.

[Swimmingorchids]

you might have enough of a difference from natural sunlight to not need anything else.

Otherwise I use a heatmat. For some I use 2 heatmats, timers and thermostats to get the right day time and night time temperature.

reptile heatmats work. A water heater in a water pot works (cheapest), greenhouse heaters work.

Up to you to decide how much equipment you need cause 2 timers, 2 thermostats and 2 heatmats is already expensive not to mention a growlight and a £20 fan that uses £20 electricity in a year that everyone on here seems to think is essential.

You can also avoid a thermostat and set up a timer in the right intervals to keep the temp right but that needs some monitoring and adjusting to start with.

Finally it really depends on the variety you grow. My zygopetalums I keep as cool as possible for our climate.

The phalaenopsis I don't use any heating and use the natural sunlight to achieve a 4 degree difference (C).

My dendrobiums get a bit of heat during the day.

My vanda's get monitored and heated to the right temps day and night.

[richardb]

Ray is quite correct. Yours sounds like about a 3ft tank. One of my other hobbies is tropical aquaria where I have a 5ft tank with lighting and yes, the T5's do get warm so the temperature will rise when they are on then drop back when the lights go off. More important though is ventilation. I assume that with T5's your tank will have a closed top to make the light aim downwards so although that will retain humidity there will be no air circulation. You will probably need to adapt your cover to include something like an old computer fan to draw air through the tank just to keep the air inside from becoming stale.
I looked into this a couple of years ago when after nearly 40 years I had big problems with my big tank and considered doing what you are planning...making it into a sort of Wardian case.

[JKeys]

Thanks y'all! This is really helpful, it is always an interesting challenge to change the setup so frequently. Appreciate your feedback I've brought the lights in and yes, you're right -- they do heat things up a bit. So, I think that will work just fine. I do love the idea of using an old computer fan, sounds less expensive way to recycle some old material. Now off to find some old computers...

[Swimmingorchids]

I finally got round to digging out some old fans and solar panels from the attic - this is what I made. Works at full speed on a really sunny day



optional extra: just found this on youtube which I will be making as a mini humidifier (with water instead of ice) but will definetely make one of these for the summer also

[Ray]

One question none of us has thought to ask is "do your plants need a day/night temperature differential?". That, of course, will depend upon what particular plants you have.

Low altitude, tropical plants like phalaenopsis, for example, don't. What they may need is a seasonal reduction.

[WaterWitchin]

Good point, Ray. "Need" is a relevant question, especially for someone at school, with a relatively small collection... and likely a small living area.

[Swimmingorchids]

Originally Posted by Ray

One question none of us has thought to ask is "do your plants need a day/night temperature differential?". That, of course, will depend upon what particular plants you have.

Low altitude, tropical plants like phalaenopsis, for example, don't. What they may need is a seasonal reduction.

I did actually mention that but if it was cause you are ignoring me then all good too.

Currently testing temps in my new IKEA overwintering box

[Ray]

Originally Posted by Swimmingorchids

I did actually mention that but if it was cause you are ignoring me then all good too.

Sorry, Swim - I guess I missed that.

I'm not ignoring you at all. In fact, in another thread where someone was asking a "what's wrong" question, you asked if the problem might be fusarium (something you said you had yet to see first-hand [lucky you!]), and I had not even considered that. Nobody can be certain from a photo, but good call!