I have heard bad things about Schultz but it is all relative. It depends on your watering style. I hve heard Schultz mix likes to stay wet and if you water often the that is a bad mix.
It really depends on what your Cattleya is. Is it an SLC, BLC, Cattleya or is it anything else. Some Catts prefer warmer growing conditions and some more on the intermediate side. Typically, all of them love lots of bright indirect light. If it does not bloom then it needs more light.
Fertilizer is all relative as well. Most orchid specifics are fine and just follow directions but you can use any other type of fertilizer at 1/3 strength. here is some info I have compiled and noted over the years.
Cattleya are some of the most commonly grown orchid plants, and their culture is
often used as the basis for comparison with other types of orchids.
The flowers in Cattleya and their related hybrids come in most all colors of the
spectrum. Culture varies only slightly among most of these groups; this cultural
information is a general guide to"standard" Cattleya culture.
Like most other cultivated orchids,Cattleya are epiphytic, or air plants.
Because they are epiphytic they have developed water-storage organs, called
pseudobulbs, and have large fleshy roots covered with a spoungy water retentive
velamen. They are accustomed to being dry at the roots between waterings, and
therefore should be potted in very porous, free-draining media.
Light is one of the most important factors in growing and blooming Cattleya,
whether in a greenhouse setting or in a home. Bright light to some sun must be
given to the plants but no direct sun in the middle of the day. this means an
east, shaded South(as with a sheer curtain), or west window in the home, and
30-50% of full sun in a greenhouse (3000 to 5000 foot candles). leaves should be
a medium green color.
Recommended temperatures are 55-60f at night and 70-85f during the day. Seedling
should have night temperatures 5 to 10f higher. A 10-20f differential between
day and night is recommended, especially for mature plants. Higher day
temperatures can be tolerated, if humidity, air circulation and shading are
Water should be provided in two ways; in the pot by watering and in the air by
humidity. Watering in the pot is dictated by many criteria-- size and type of
pot, temperature, light, ect. Mature Cattleya need to dry out thoroughly before
watering again. Seedlings need slightly more constant moisture. Compare the
weight of a dry pot of the same size and type of medium; it can indicate if a
plant needs water. if in doubt, it's best to wait a day or two before watering.
Plants in active growth need more watering than plants that are resting.
Softened water may injure plants.
Cattleyas should be provided 50 to 80% relative humidity although this is not
necessary. Air should always be moving around the plants to prevent fungal or
bacterial diseases, especially if high humidity and/or cool temperatures exist.
In the greenhouse the humiditycam be increased by wetting the floor. Evaporative
cooling increases humidity while cooling the air.
Fertilizer must be given to Cattleya on a regular schedule. In fir bark, a high
nitrogen (30-10-10) formulation or a similar proportion is used. high
phospherous or bloom-booster ( 10-30-20) formulation may be used occasionally
(every 4 to 6 applications) to make sturdy growths and promote healthy blooming.
When in active growth, plants need fertilizer every two weeks, and when not
growing, once a month. Fertilizer can also be applied with every watering at 1/4
recommended dilution. Thorough flushing with clear water every month is
recommended to prevent build up of fertilizer salts.
Potting is necessary when 10 the rhizome of the plants portrudes over the edge
of the pot, or 2) the potting medium starts to break down and drain poorly
(usually after 2 to 3 years). It is best to repot 1) just before new roots
sprout from the rhizome, 2) after flowering, or 3) in the springtime.
Cattleya are usually potted in medium-grade potting material, with seedlings a
fine grade. Until a plant has six mature pseudobulbs, it generally should be put
into a larger pot and not divided. If dividing a plant, 3 to 5 bulbs a division
are required. Select a pot that will allow 2 to 3 years of growth before
crowding the pot.