Varying your irrigation concentrations

[richgarrison]

Just curious about folks watering habits....

I suspect many of us vary the composition of our irrigation water based on season (which would be interesting to see)

How many folks vary their irrigation concentrations based on how sunny it is the day they are watering or any other environmental conditions at the time of watering?

 

[Ray]

For the last 8-10 years, I have NOT varied solution a bit. The weather dictates the frequency of irrigation, and that affects the mass of nutrition they get.

 

[richgarrison]

Ray - do you have plants that you water everyday, regardless of weather.

 

[Ray]

No. The closest thing might be tolumnias mounted on a piece of cedar board, but I will sometimes let them go for a week, if it's cold and gray.

 

[richgarrison]

side note - I'm always torn between 'that was a good conversation, should i just leave it at that? or should i reply saying 'that was a good conversation thanx'... This time i'm picking the reply...

Thanx for the interaction Ray.... the motivation for this thread was that i've moved my slippers into a mix that supports (very?) frequent watering and a couple hundred vandas that are growing 'on a wire' and i should water daily... i finally got my RO rig setup about a year ago, and have been evolving my irrigation /fertilization setup over time... and thought i was settled in there...

...but i was still noticing soft growth at times, and more irwinia than i thought i should have...

i finally did some calculations yesterday that i should have done long ago, and saw that i was feeding in the 50-75 ppm N everyday in my phrags and every other day or so on my paphs... my TDS measurements are in the 130 to 280 micro siemens level. i was assuming that with TDS measuring that low, my N 'must be very low'' doh! Ass U Me yes indeed....

so more tweaks in order...

Again Ray thanx for you info...

 

[Ray]

i finally did some calculations yesterday that i should have done long ago, and saw that i was feeding in the 50-75 ppm N everyday in my phrags and every other day or so on my paphs... my TDS measurements are in the 130 to 280 micro siemens level. i was assuming that with TDS measuring that low, my N 'must be very low''

µS is electrical conductivity, not TDS, which is a concentration. Two different fertilizers, when used at the same ppm N, will have different EC and different TDS.

For example, MSU WW (19-4-23-2Ca), MSU RO (13-3-15-8Ca-2Mg), and K-Lite (12-1-1-10Ca-3Mg), when applied at 50 ppm N, will give ECs of 0.34, .040, and 0.35 mS/cm, respectively, in addition to whatever it is for the water supply used.

 

[richgarrison]

µS is electrical conductivity, not TDS, which is a concentration. Two different fertilizers, when used at the same ppm N, will have different EC and different TDS.

For example, MSU WW (19-4-23-2Ca), MSU RO (13-3-15-8Ca-2Mg), and K-Lite (12-1-1-10Ca-3Mg), when applied at 50 ppm N, will give ECs of 0.34, .040, and 0.35 mS/cm, respectively, in addition to whatever it is for the water supply used.

Yes understood i was using sloppy language there... i have an electrical conductivity meter that also provides a translation to TDS.. i used both the conductivity measurement of my actual irrigation water and the projected conductivity provided by the fert manufacturer for a given N concentration to back calculate what i expect the N concentration of my solution is... Hoping that makes sense... the obvious reasoning being that there's a lot more in the fertilizer than just N...