Potting mix
 

I have to buy my potting mix at the Big Box Stores or the net.
Here are pictures of 3 different ones. I have Phals, Cats and Oncs. The first bag says for all three, the 2nd leaves out Oncs, (Its much finer, Im out) and the 3rd is a mixture of coarse and fine. I need recommendations.

The one on the left is very coarse. I would use it for cattleyas, and maybe phals with frequent watering.

The one on the right seems to fine for cattleyas, but again, it could work. I would use it for phals and oncidiums for sure.

The one in the middle, I think I have bought the same one from HD once as I was curious to see if it is as good as ones I get from online (which is generally more expensive and extra money for shipping).

Well, it could have been just the particular bag I bought, but the bark was of HORRIBLE quality.
I could touch them gently and they broke into dust.
I threw it away and ordered from online. lol

I think you are right about the center one. It was pretty fine for saying coarse and was not as sturdy as the others. I have been mixing some of those clay balls in the latest potting, I think I like the one on the right best and its the cheapest. HD your right.

I don't like any of the store bought mixes or bark...they seem to be like steamed or something that makes them fall apart quickly...I prefer to order high quality bark from repot me or kellys korner...your cattleyas will certainly appreciate it, and so will your other plants....you will spend less time repotting also....the special mixes for paphs and onc are finer bark, but last well too....you just get a better quality and it is definitely worth ordering....the box store brands besides not being good enough quality and soft, allow for insect infestation by staying 'soggy' and soft....good luck!

It's important to know what conditions you're growing in also. Are you using clay pots or plastic pots? Are you growing outdoors or indoors or in a greenhouse? Do you tend to overwater or underwater your plants?

Indoors in a garden room, in the summer I can open all the windows. I have fluorescent lights on the Onc's and Cat's.
I have a oscillating fan one hour on and one off 24/7. They are in a window that gets evening sun through the trees. The Phals bloom every year. This is te first year on the lights and I have had 2 oncs and 2 cats bloom, one in bloom now and 4 Phals. If iI had to guess it would be underwater, although sometimes it appears that they are still wet after 1 week to 10 days. Plastic pots with bottom holes, some with slits and some with a cone in the bottom, some round some square and some opaque, (only Phals) The rest clear.

I have had pretty good success with the Better Gro Bark, Better Gro Phalaenopsis mix (=bark, sponge rock & charcoal). It has been a very long time since I used the Schultz mix, can't recall enough to offer an opinion on that one. I have not tried the Miracle Gro mixes, but I know they have a reputation for containing a lot of fine particles.

Sometimes I have used the Fafard orchid mix (also found in big box stores sometimes), which has bark, perlite, coir and coconut husk chips. It seems good for orchids that need a lot of water retention, but rinse it well (due to the coconut husk products in the mix, which can have high natural salts in them).

The better grow has the biggest pieces of bark and I do not see anything but bark and it says its for Phal, cats and oncs. Do they make different mixes?

Selection of mix depends on not only which orchid groups you have, but also on what watering schedule you want to maintain, and what pot type/size you are using.

I used to buy ingredients in bulk (from Roberts Flower Supply in OH), so I could blend for different purposes. Now I buy ready mixed for Cattleya & Paphs from Waldor Orchids in NJ, and add finer bark or charcoal when I need it.

So I assume you mix it so you can water all at the same time regardless of type?