What caused these black patches on my Bodi tree leaves?

Some of the leaves on my bodhi trees developed some black, almost burnt looking patches on the leaves.

I have been keeping two bodhi trees in my "fish house" (a room 80 degrees F @ 80% humidity) and these trees and cuttings have been growing well under a 400 watt agrosun gold HID light.

I did recently move the trees outside during the days a few times recently when the temps were above 55 outside.

Might the move to the colder air/draft have caused this problem, or is it the suddenly stronger direct sunlight or some other thing like a different PH watering that could have caused this??

The trees are doing very well, but I would like to know what caused this so I can avoid repeating it.

Thank you in advance :)

Plants that are accustomed to stable, warm, humid conditions can get a shock moving out to a mild day where the air is drier, and colder than they are used to.
Those spots look more like cold damage than sunburn.

Ok,

Thank you.

I am also in contra costa county :)

So is it possible to acclimate/harden the tree by more regularly moving it outdoors (just during the sunny part of the day) when the weather is nice outside?

I am not sure if it would grow outdoors through the winter, but you could make it a patio plant through the summer.
Slow acclimation is the key.
On some of those nice mild days in about April or May just take it outside for an hour or two, and in an area that is not much brighter than the light it has in the greenhouse. Perhaps dappled light under a tree.
Each day leave it out a little longer. Avoid the wind, too.
With the odd weather that sometimes happens it might take several weeks to work up to leaving it out all day. Probably by the end of May.
If you can group it with other plants that will help with the humidity issue, too.

Remember to check for pests before bringing it back into the greenhouse.

What do you grow in your greenhouse? I also have a greenhouse, but it is more of a fish room. Lots of aquariums in there.

Yours is a fish room too??

I have a 12 x 24" building with 1 1,400 gallon pond, 3 400 gallon tanks and 4 75 gallon tanks, all at about 83 degrees.

All I'm growing in this room are the two bodhi trees and a bunch of their cuttings under a 400 watt Agrosun gold bulb.

Mine is 17' x 20', has only 1 pond, and 30 tanks. I have a couple more tanks in the house and another pond in the front yard.
Total gallons: about 1,500.

How are you heating it?

All electric heat in water, but gas tankless heater for the large water changes.

Breeding Asian Dragonfish :)

That takes some serious gallons! Big fish!

Must cost a bit to heat with electricity.

Just bought a 11.3 KW solar system :) Now paying 9 cents per KWH :)

Some of my fish are 5 lbs and over 24" I go snorkeling with them. Very fun.

My largest arowana tank is 3800 gallons.

I have a very tolerant wife.

I need to go solar for mine, too. Did you install it yourself? Or go with a contractor?

Installed everything myself, except for having the Inverter wired for me, only $700 for that.
My first system was 16 260 watt panels, total installed cost including new roof, less than $10,000.

If you are interested I would be happy to share the fruits of my research.

I'm paying less than 10 cents per KWH :)

My direct email is nicefishtanks at gee mail dot com.