Growing orchids in a passive hydroponic system, commonly referred to as growing in semi-hydro using LECA (Lightweight expanded clay aggregate) which is an inert clay material and contains no nutrients. It is easy to use, it's clean, you can't over water, you will have less problems with disease and insect pest's. And no more re-poting every two or three years! just pot up to a bigger pot when needed, no more having to remove old media and probably the only dead roots you will see are the original roots which didn't adapt to the clay balls.
For pots any type of container can be used, clear plastic drinking cups of around 250ml and up work well as starter pots. Clear take away containers are fine for bigger plants which will need a 5" or 6" pot.
With a soldering iron place a couple of holes about 2 cm from the botttom to create a reservoir, for larger pots allow about 20% of the pot for the reservoir.
Fertlizer needs to be kept to a minimum, 1/2 strength (of what? use the EC meter!) or maybe even less, and needs to contain everything the plant needs, mainly calcium and magnesium which in most fertilizers is present in very low quantities or absent. Best bet is to use a fertilizer designed for soilless mediums. Also get youself a TDS meter to keep a check on fertlizer strength.
Avoid any fertlizer with a high percentage of ammonium nitrate, can be toxic to some orchids.
Water as much as you like , the more thr better as this will keep the leca free of salt build up.
Tthe important thing is to try to use good quality water low in salts, and to resist hitting your plants with high doses of fertilizer and flush with clean water often.
There is a lot of misleading information online, so many different ways of growing in clay so don't stick to any one persons method as it may not work for you because their conditions will most likely be different to yours.
Start with just a few orchids in this medium and use good quality water, low strength nutrient and a sharp lookout for any sign of salt build up, you will find what works for you.
For more information check out www.firstrays.com
Rockhampton Water Quality as of 5/10/2017
EC uS/Cm .225 PH 7.8
This is the quality at our place, and does not reflect the whole of Rockhampton