How much MSU is Weakly Weekly?

[Ray]

Originally Posted by euplusia

I check my fertilizer concentration by measuring the conductivity of electricity. When I put the recommended amout of MSU in rainwater, it gives about 1600 mikroSiemens. Thats pretty much for orchids.
For comparison: Pure rain in the city is 40 mS, well water 400 - 700 mS. For Masdevallias I gave rain enhanced with fertilizer up to 300 mS once a week. For cattleyas 600 mS once or twice a week, but not only into the pot, also over the leaves. Catasetums in summer in active growth 800 mS.
The recommended concentration may be fine if there is enough light and warmth and the plant is a strong grower and in active growth. Otherwise 30 - 50 percent of the recommended concentration diluted in rainwater is enough for my plants.

According the the Greencare labels (the original MSU fertilizer formulas), a solution made up for 100 ppm N will give EC levels of 800µS (RO formula) or 680µS (Well Water formula) over the reading for the plain water.

I don't know who is "recommending" the level, but it's way too high.

[euplusia]

Thanks Diskus. Mikro should read µ and not m (milli). I've edited the post.