I've checked at different times, seems with lights on temps go up to about 68-69. After the lights have been off for nearly the entire "off" cycle, temps only get down to 66 at the lowest.

I'll check out that FAQ. Thanks!

I would think about adding a small fan. Without sunlight and air circulation you might get mold problems.

Ok, I'll be adding a fan this weekend then.

James, you don't think the non-fluctuating temps are a problem?

I don't think it will be a big issue. how are you measuring the temperature. I use a infrared thermometer, the air temp could be different from the leaf temp in the light.

I just have a cheap thermometer/hygrometer at the level of the pots

I think it will be an issue when trying to get flowers. Most hybrid phals need a 15-20 day/night temp drop in the fall to initiate buds. In my indoor area (spare bedroom), I open a window at night in autumn to help get the differential in temps.

I'm in zone 6 and also put all of my mature phals outside from May - September'ish. That in itself gives a lot of them the natural temp flux they need to initiate spikes.

Species phals are usually different, depends on species for specifics.

Personally, I'd throw another 2 light flouro fixture in there, as the phals can take/prefer more heat than 70 or so, and there is never too much artificial light.

Good luck,

Bob

I agree that if you want blooms, you're going to need a 20 degree temp dip for a while. Otherwise, I guess it sounds fine. I have zero experience growing under lights so I have no experience on that.

What if you set up the fan on a timer to come on when the lights go off. I think you would get more of a temperature drop from evaporation of the water trays.

I suppose eventually I'll either have to regulate the temperature or move the plants. They're rescues/clearance from lowes and for now I'll just see how they do, and add a fan. I guess the best thing to do would be put them in my spare room with a southern facing window. Doesn't receive the best lighting due to trees and my neighbors house. I guess then I could supplement with the fluorescents and buy a humidifier. Temps will fluctuate more here, obviously, and of course I want them to bloom again!! The reason I originally chose the basement was due to the constant humidity and the unsightliness of my makeshift grow area. Think I'll get a decent shelfing unit eventually and put it in that spare room. In zone 6b if it makes a difference.

Any other tips for now?

I'm surprised that you haven't had more response. Surely in very cold climates growing in a basement would be better than carting orchids in and out or taking over parts of the house.

Have you thought about using an electric heater to lift temps a little and an exhaust fan to vent air if required.

There must be some sort of North boundary where having a heated glass-house becomes just

too expensive.

It have thought about getting a heater. Since I'm growing in such a small space it wouldn't be much as far as cost is concerned. I guess that's kind of what I was looking for in my post, if extra heat was needed. And it sounds like most responders agree, I need more heat for blooming.

But the spare room I was referring to earlier is just that... A spare room. I only have items in there as storage. So setting up a growing area there wouldn't be taking over used space. And it would have more of a temperature fluctuation that orchids need.

I think that'll be the next project...

Did I miss where you live?

Why can't you put the Phals outside in summer until early Fall to get natural drops in temps. I grew my Phals in NY and they would start to spike in September (I brought them in when night temps dropped below 40F). As the temps got colder I brought them in and put them under lights. They finished growing their spikes and bloomed very well.

You need those temp drops in Fall to initiate spikes. Once that starts, you can bring them inside and the lights will continue to grow the spikes.

Put them out in summer/fall.

Jane

Zone 6b. I don't get too much light outside due to trees. Best place is the above mentioned spare room

So I moved the plants to my spare room today. I have yet to set up the lighting... battery powered screwdriver died. I'm estimating that the area the plants are in get 3-4 hours of sunlight, then a large tree filters the light for another 3 hours, mind you it filters a lot of the light so not much gets through. Should I supplement with my fluorescent bulbs? If yes, how much do you all recommend? Should I just keep them on the entire 16 hours I was before? Plants are again in a tray with rocks and water, today the humidity has been about 60% and temps mid-high 80s. I'm expecting temps to be low 70s at night as I only have the AC on during the night (it's a warm upstairs bedroom). Any thoughts?

Light is stronger outdoors even if shaded. Windows cut back on light. If they were my plants I'd put them outside where they could get some decent light.

Jane

Everyone always says to put these plants outside but like you I have been growing my orchids in a spare bedroom for about 6 years now in an environment similar to yours.. Orchids like air movement so can you add some sort of fan! I have a ceiling fan turned on low that runs 24/7. Humidity sounds fine. I have a hygrometer/thermometer in there and check it every day. I keep a humidifier in the room and I only have to run it this time of year, usually in the daytime when the A/C runs a lot. Temps sound fine too. I bet they go down at night when the lights go off. I don't think you need to keep them on for 16 hrs/day. 13 hrs would do fine. As for light go by the leaf color. They need to be a nice bright medium green (I hope I'm describing it correctly). Look at phal photos at the orchid gallery for leaf color. I too open both windows at night for about 3 weeks in the fall when our temps are in the 50s for that 10-15 temp drop they need to throw spikes.