My Phalaenopsis regimen
 

I'm really new to growing orchids, I picked up most of the leftover Mothers Day orchids at our local Walmart last June for pennies on the dollar as I wanted to give orchids a try. I started with 23 and am down to 15 which seem to be doing very well and currently have quite a few in bloom. But what I really wanted to find out was am I taking care of them right. I water about every 8 or 9 days using Better-Gro 20-14-13 orchid food mixed with distilled water. As time comes around for the 4th watering cycle I use just plain distilled water on all the orchids to flush them out. I mist my orchids twice a day using Ultra Clean Potassium Nitrate 13.7-0-46.3 1/2tsp mixed in 1gal of distilled water. When repotting I've been using Rexius Orchid bark and 6 1/2" clear pots. I have them all sitting on my homemade humidity trays which seem to work pretty well out in my greenhouse. The greenhouse is covered with 60% shade cloth which I've just put on this year so I'm hoping it will cut down some on the heat inside. I've also figured out a way to run power to it so I can get some fans going. The attached photo is of my humidity trays.

If you are using distilled water, be certain that your fertilizer has Calcium. All plants need Calcium. There are some other nutrients that a plant needs, too, but often a plant food has them in small amounts. For some reason, it is rare to see Calcium added.

Thank you, I'll check the ingredients on the fertilizer and see what all is in it.

Keep an eye on that aluminum humidity tray. In time it will develop small pin holes in it and it will begin to leak.

Thanks, good thing to note, I'll keep an eye out. I also use a little bit of algae killer such as is used in swimming pools to keep algae out of them.

Thinking about what gngrhill said and having seen what another grower on this forum has done (sorry, I can't recall exactly who), you may want to consider eventually replacing the aluminium trays with cat litter trays or similar plastic trough.

Thank you, that is a great idea. I don't know why I didn't think of it. I guess I was going for cheapest as possible.

Adding a bit more to my thread. I checked my Better-Gro food, no calcium listed at all. So, what I did was ordered some calcium nitrate the other night. Since I'm misting the orchids once in the morning and once in the mid-afternoon w/distilled water and potassium nitrate would it be ok to add 1/2tsp of the calcium nitrate to the gal of distilled water that I mix the potassium nitrate into for misting? Would misting with this combination be too much for the plants? Or, should the calcium nitrate be mixed into the distilled water I use when feeding/watering which is about every 8 or 9 days currently.

I personally would not add anything to water I used for misting because it will eventually leave sediment spots on the leaves. I would add any supplements to the water I water with. Also, It's not really known how much the plants can absorb/use from foliar sprays.

So your suggesting that I just mist with plain distilled water and any supplements I'm going to add I add when I feed them. Then it would be ok to add 1/2tsp of the potassium nitrate and calcium nitrate to the 1/2tsp of fertilizer I'm mixing into the distilled water?