Which MSU formula should I use?

[FrankP999]

My municiple water test from my faucet showed:

Calcium 11 ppm
Magnesium 2.4 ppm
Bicarb 43.3 ppm
Alkalinity 35.6 ppm
Sodium 9.7 ppm
Phosphate 2.4 ppm

Which MSU formula should I use - Pure Water or Well Water?

I will be using Kelpak also.

Thanks

Frank

[Ray]

You could probably use either, but the Well Water version is probably adequate.

If used at 125 ppm N, the RO formula will provide 43 ppm Ca and 26 ppm Mg, both of which are more than your water has. However, as you supply the minerals in the water every time you water, while you may not feed that frequently, it's probably adequate in the long term.

[FrankP999]

Ray, I tend to fertilize every time I water with 125 ppm dilution. In that case, would you still suggest the well water? Is there any downside to using the RO formulation? Thanks

[Ray]

I seriously doubt that the extra calcium and magnesium you'd be providing your plants would present any issue.

The decision is probably economical, more than anything else: at the same N concentration, you'll get 45% more gallons per pound of dry fertilizer from the Well Water formula.

[keithrs]

If your going to fertilizer with every watering, I would go with a much lower ppm N. I fertilize every watering with k lite @ 15-20 ppm N. I use to use 125 ppm N every watering and found that I was way over doing the N and backed down to 80, than 50, and I'm at the current. I'll amit that I have only been at these level for several months but the results seem to be good.

I will add that I believe that your better off going with ro ver. It's been said that Ca can be about equal to N in ppms. If you plan on feeding with 125 ppms N, I don't think your well water will supply enough Ca or Mg.

[Ray]

125 ppm N (MSU RO) at every watering didn't harm my plants over the 6-7 years I did that. I guess it depends upon how often one waters. If you think of a watering as a "meal", and the concentration as the "calories", once a week at 125 is probably as good as twice at half that.

Like Keith, I have backed off - to about 75 ppm N in my case - and am happy with the plants' performance.

[keithrs]

I will clarify that nothing dramatic happened except the leaves on a few plants flopped over instead of being ridged and all my plants had a very dark green cast. Growth rate with my current rate has been about the same as before.... A little slower.... Which I prefer