Questions about fertilizing
 

Just started using Shultz liquid orchid food 15-5-5. In says to use 7 drops to 1 litre water. With EVERY watering.
Should I go with the directions or do a weaker solution fewer times?
Some of my plants are in (early) spike, some are in flower, some have just finished flowering and some have yet to spike for the first time. Should I use it on all of them?
Any other considerations?
Thank you

While the dissolved ingredients might affect it a bit, generally speaking, there are 20 drops per ml.

2.3 divided by the %N on the label gives the ml/L for 25 ppm N, so that would be 2.3/15=0.1533 ml.

7 drops is 7/20 or 0.35 ml, so their recommendation is around 50 ppm N, or so. Whether that is the proper level depends upon how often you water. Personally, I shoot for 75 ppm N applied weekly, so if you water once a week, I'd go with 10 drops.

Surprised to see that called 'orchid food'. 15-5-5 is not exactly balanced.