Light supplement for seedlings

[Yéri]

Hey everyone,

I have a small greenhouse (actually a part of the sunporch closed off from the rest) to grow my orchids in.

I get medium amount of light and humidity stays around 60% during winter as I have central heating in the greenhouse and the air dries out more easily.

I have about 50-60 seedlings I think, I tried out deflasking etc. last year and well...moderate success.

I feel the light and humidity are a bit too low for my seedlings to be healthy, so I thought of adding a miniature greenhouse inside my actual greenhouse.
This is it the model, mine is smaller houten kweekkas zonder verzendkosten - kweekkas te koop van hout - houten kweekkas

Of course, I could keep my seedlings with higher humidity with a fogger in there, but the lighting will be lower in there because of the extra layer of polycarbonate...

So I was thinking of using these LED tubes in order to supplement some lighting:
60cm 10W 140° radius 1022 lumen 5700K

Would 1 be sufficient to supplement lighting on a 30cmx60cm area? I was thinking of hanging the tubes at 20ish cm off the plants.

Also, as you can see there are several layers on which I'm going to put my seedlings. Would the bottom part require significantly more lighting?

I'm happy to hear any comments you have on this project.
Alternatives are always welcome, but I found these LED tubes at 25€ (with starter) and consider them the best option regarding price and energy savings.