FlytrapCare Carnivorous Plant Forums

Hey everyone, I don't contribute much here but I am asking for help, hopefully someone has some ideas for me.

I'm trying out my old Metal Halide / High Pressure Sodium system for growing carnivorous plants. Most of my plants seem to be doing well so far, but the main issue I have noticed is heat buildup.

I have an electronic 250 watt dual MH/HPS ballast with your standard Home Depot-bought Sylvania Metal Halide bulb, installed with the cheapo reflector I got for free with the setup. I brought the plants in from the fairly cool nights we have had since fall started, so I think some of them are still in shock, like, "WTF happened we were just getting ready for winter and now it's 85 degrees!!" Here are a couple of pictures showing the setup as I have been running it for about a week. Half my plants are inside the 2.5gallon aquarium in back, the VFT's and other things that can handle drier conditions are in front.


Sorry if the other plants are in the way, I'm trying to see if sweet peas will root in plain water. There is a tiny D. rotundifolia and another King Henry you can't see in the aquarium

The problem is that by their nature, the bulb and reflector start to get very hot as soon as the light turns on. By the time I get home each day some of the plants outside the aquarium have nearly dried out already. To solve dryign out the first thing I guess I should do is get a big tray for everything outside the tank, but that still leaves the issue of excessive heat, both from the light itself being absorbed and re-emitted and also radiative heat from the bulb.

I know I can solve the problem by going out and spending $100 on a new cooled reflector, but I don't really want to invest in something that expensive for just a side hobby. I would ideally like to convert this reflector into something better without much cash investment. I have tried taping a piece of plexi to the reflector and it works for a bit, but the hot sides of the reflector are very hot and the adhesive quickly melts once the light is on for a couple hours.

First thing I need to try is moving the thing away from the wall, that should let a little more heat escape to that side.

The main tip I like so far is trying to find an aluminum mailbox and cut a hole in the side for a fixture, but those are nearly as expensive as a reflector! I will keep an eye out at the thrift store, but I decided to come here and see if anyone has any experience with HID's and carnivorous plants, or even if you have ideas for keeping the heat up and away from the plants.

I don't know how well this would work since High Pressure Sodium bulbs get super hot, but I know I can keep the hot air off my T5HO bulbs (which do get decently hot) by placing a fan at a slight angle along the bulbs (so the fan is not quite parallel, blows against the bulbs, keeping the hot air away from my plants).

Does your bulb raise the ambient temperature of the room? Or just the area under it? If it is just the area under it, using a fan should help should help.

I thought about the fan, but then realized it would kill any humidity left and probably dry the plants out even faster. I am beginning to think I should just switch to fluoros too, or find some way of getting the bulb farther away or insulated without killing the light.

I have noticed that the fly traps are doing great, because I think they can tolerate the lower humidity/higher temps better, but the sundews are starting to suffer. Seedlings are doing good, but the capensis is starting to get its tips scorched especially near the top-heat rises so that makes sense. I believe I might take the tank out today and put a couple of CFLs over it for the moment.

If the fan isn't blowing on the plants then it won't do much to the humidity (as long as the plants are standing in water). You don't need an exceptionally strong fan, just one that will keep the light cool.

I am also using pc fans to blow the heat from my t5 lamps. This works great.


Verstuurd vanaf mijn G620S-L01 met Tapatalk

Hey that's a good idea, I have rigged up PC case fans to cool this light before, so just getting some air blowing over the bulb might work.

Here is a small update, I got a white tray to keep all the plants in, which will save me needing to water each and also seems to have helped the heat a little, since the light falling past the plants is mostly reflected instead of being absorbed and heating the table up. I also moved the little tank off to the side so that it's not so hot.



This guy is growing quickly, it seems to enjoy the new light:




This D. binata was about to go into dormancy growing outside, I hope it doesn't mind being forced this winter


D. spathulata is also enjoying being warmer


The fly traps are also enjoying it, first one is in the open and the second is in the "terrarium"




This d. spathulata is in the terrarium, it got too hot at first but now it's doing well. The seedlings are D. capensis


These are D. capensis seedlings, they came from a supposed alba specimen but appear to have a little red in them


This shows how the big D, capensis got burnt near the top, see how there's no dew at the tip?


Anyway it looks good so far, I think the tray will really help with humidity and also a little bit with the heat level. I will also try hooking up a small fan to the light fixture, but I am starting to lean toward getting a nicer reflector like one of the "adjust-a-wing" types at some point, since they are actually only around $70

Even without a fan (I haven't had time to set that up) things seem like they are going well. I have the light about 12 inches from the plants and it seems to be a good equilibrium between light and heat.

Sorry about the so-so photos, the diffuse light makes it hard to get good contrast

D. binata about to open up


Hybrid purp less than a week since the last pic


D. spathulata recovering from transplant, there are some seeds just sprouting as well


Happy fly trap


Here you can see the ridiculously long and thin summer traps it made earlier this year


These got cold in the window and had no dew, now there are recovering


D. capensis alba seedlings almost ready to transplant


D. spathulata with D. capensis seedlings


You can see how this capensis got scorched from too much heat, but it's recovering