I think your problem is probably too much water in the medium, which causes there to be an unhealthy lack of air in the rootzone. If it's not excess water, it's probably due to an excess of salts in the soil that are found in tapwater & fertilizers. You don't have an ion exchange water softener, do you - the kind you have to fill with salt at regular intervals? Too much water in the soil affects the root's ability to move water to the foliage, and can even cause infections resulting in root rot. The good news is, the negatives associated with soil saturation can easily be eliminated to a large degree, even if not completely. Here's how: Next time you water, water over the sink Use water that feels slightly cool on the back of your hand. Flush the soil very thoroughly by slowly applying to the top of the soil a volume of water equal to what you'd guess to be at least 10x the volume of the pot the plant is in. This will dissolve most of any salts that have accumulated in the soil. When the pot has stopped draining, hold it in both hands and move it up and down over the sink. You'll note that when the motion is reversed from down to upward, excess water from the pot will exit the drain hole. That's Newton's first law of motion working for you. ;-) You'll also note that the sharper the change in direction, the larger the volume of water that exits the pot. Keep doing that until water no longer exits the pot.

Try to stop watering on a schedule if possible. You can use a "tell" to tell you what moisture conditions are deep in the pot. It's much more effective that a finger, just eyeballing it, or guessing. I'll leaf something I wrote at the end of the post.

Don't let your head explode over the numbers in the fertilizer info to follow - it's not that critical that you understand it right now. Most fertilizers designated specifically for 'houseplants' have much too much phosphorous in them. Schultz 10-15-10 is popular, but plants use about 6x as much nitrogen as phosphorous. The Schultz product supplies about 4x as much P as the average plant wants or can use, which creates issues that increase in seriousness as the amount of fertilizer in the soil accumulates.

Elena is on the right track, but she wasn't quite correct. The 3 numbers on fertilizer packaging are representative of the %s by weight of nitrogen, phosphorous, and potassium, in that order. If you remember your math you'll recall that, if you have a dozen eggs, 4 pieces of toast, and 8 slices of bacon, the RATIO of eggs to toast to bacon would be 12:4:8 or when reduced, it would be 3:1:2. A fertilizer with NPK %s of 2-2-2, would be a 1:1:1 ratio. 3:1:2 ratios like 24-8-16, 12-4-8, and particularly 9-3-6 are all very good choices. Personally, I use Foliage-Pro 9-3-6 for everything I grow. I doctor it a bit for tomatoes and hibiscus, but that's all I use, otherwise.

Why don't you see if you can get your plant stabilized by using the advice above. After it's regained some vitality and has some stored energy reserves, we can get it repotted.

Last thought, it's a rain forest epiphyte that does well in low light and likes high humidity. Low humidity can spoil foliage, so that's a consideration, too.

This might be useful.

Here's the info on using a "tell" (below).

Using a 'tell'

Over-watering saps vitality and is one of the most common plant assassins, so learning to avoid it is worth the small effort. Plants make and store their own energy source – photosynthate - (sugar/glucose). Functioning roots need energy to drive their metabolic processes, and in order to get it, they use oxygen to burn (oxidize) their food. From this, we can see that terrestrial plants need air (oxygen) in the soil to drive root function. Many off-the-shelf soils hold too much water and not enough air to support good root health, which is a prerequisite to a healthy plant. Watering in small sips leads to a build-up of dissolved solids (salts) in the soil, which limits a plant's ability to absorb water – so watering in sips simply moves us to the other horn of a dilemma. It creates another problem that requires resolution. Better, would be to simply adopt a soil that drains well enough to allow watering to beyond the saturation point, so we're flushing the soil of accumulating dissolved solids whenever we water; this, w/o the plant being forced to pay a tax in the form of reduced vitality, due to prolong periods of soil saturation. Sometimes, though, that's not a course we can immediately steer, which makes controlling how often we water a very important factor.

In many cases, we can judge whether or not a planting needs watering by hefting the pot. This is especially true if the pot is made from light material, like plastic, but doesn't work (as) well when the pot is made from heavier material, like clay, or when the size/weight of the pot precludes grabbing it with one hand to judge its weight and gauge the need for water.

Fingers stuck an inch or two into the soil work ok for shallow pots, but not for deep pots. Deep pots might have 3 or more inches of soil that feels totally dry, while the lower several inches of the soil is 100% saturated. Obviously, the lack of oxygen in the root zone situation can wreak havoc with root health and cause the loss of a very notable measure of your plant's potential. Inexpensive watering meters don't even measure moisture levels, they measure electrical conductivity. Clean the tip and insert it into a cup of distilled water and witness the fact it reads 'DRY'.

One of the most reliable methods of checking a planting's need for water is using a 'tell'. You can use a bamboo skewer in a pinch, but a wooden dowel rod of about 5/16” (75-85mm) would work better. They usually come 48” (120cm) long and can usually be cut in half and serve as a pair. Sharpen all 4 ends in a pencil sharpener and slightly blunt the tip so it's about the diameter of the head on a straight pin. Push the wooden tell deep into the soil. Don't worry, it won't harm the root system. If the plant is quite root-bound, you might need to try several places until you find one where you can push it all the way to the pot's bottom. Leave it a few seconds, then withdraw it and inspect the tip for moisture. For most plantings, withhold water until the tell comes out dry or nearly so. If you see signs of wilting, adjust the interval between waterings so drought stress isn't a recurring issue.Hi, Ellie - So you water over the sink and wait until the pot stops draining?

Al