Disa aurata

[gdupont]

Yeah, I've just been using RO water, but I think it's going to need fertilizer at some point... And some people obviously use fertilizers for Disas.

 

[naoki]

I'm not so successful with Disa, but here is a couple with both N sources:
Dyna-gro Grow has 4.4% NO3 and 2.6% NH4.
Dyna-gro Hi-N-Pro seems to be better with less phosphorous, but it is a bit more difficult to buy.
Grow More Orchid Urea Free has 12% NO3 and 8% NH4, but no Ca, Mg, and B.
Jack's Orchid liquid 7-5-6 has 5% NO3 and 2% NH4.
Jack's Peat Lite 20-10-20 has 12% NO3 and 8% NH4, but no Ca.
I think I was using MSU + ammonium nitrate.

 

[gdupont]

I'm not so successful with Disa, but here is a couple with both N sources:
Dyna-gro Grow has 4.4% NO3 and 2.6% NH4.
Dyna-gro Hi-N-Pro seems to be better with less phosphorous, but it is a bit more difficult to buy.
Grow More Orchid Urea Free has 12% NO3 and 8% NH4, but no Ca, Mg, and B.
Jack's Orchid liquid 7-5-6 has 5% NO3 and 2% NH4.
Jack's Peat Lite 20-10-20 has 12% NO3 and 8% NH4, but no Ca.
I think I was using MSU + ammonium nitrate.

Great, thanks for this breakdown! How much would you dilute the Dyna-gro Grow? In other words, how much should I add per gallon?

 

[naoki]

I measured EC of Dyna-Gro Grow.
Base dH2O: 13.70 microS/cm
At 20ppmN of Dyna-Gro (0.286ml per a litter of water), I get 222 microS/cm.

So it raise the EC by 208.3 microS/cm. It terms of tsp, if you do 1/4 tsp per gallon, you'll get 23ppm N, which should give EC of 239.5 microS/cm, which seems to be close to what is recommended by Wally Orchard. So it should be good if your base water EC is close to 0.