Encyclia (Prosthechea) Cochleata leaf spotting

[BernieK]

Hello All, Bernie here from the soggy east coast of Vancouver Island, BC canada. I have a Encyclia (Prosthechea) Cochleata that has been doing well, two new bulbs and flowering since last August but recently some of the leaves are exhibiting these blotches (see photos) mostly on the new growths. There are no signs of insects and I'm fairly certain that it's not mold and am hoping it's not a virus. I'm leaning towards maybe a nutrient deficiency but I'm not sure. The plant is grown under LED lighting and is fed using the MSU fertilizer. Any thoughts out there?
Cheers, Bernie

[Ray]

Hi, Bernie.

It does not look to be a nutritional issue to me, but to rule that out:

What is the hardness of your water supply?

Which MSU formula (19-4-23 or 13-3-15) do you use?

At what concentration do you mix it?

How often do you apply it?

[BernieK]

Hello Ray,
I use the MSU 13-3-15 during the spring, summer and fall months at 5 cc per 4 litres (1 US gallon) weekly (three times a month) with a full flush once a month. In the winter I use Dyna-Gro liquid bloom (3-12-6) and Pro-Tekt (0-0-3) at 1/4 strength weekly with monthly flush.
In winter I use filtered rain water (we get lots of rain) and the rest of the year I use tap water with TDS levels around 65-70 ppm.