Peter's Cal-Mag Excel

[isurus79]

I know that the Peter's 15-5-15 is the same one that H&R Nurseries uses. I was told, however, that the smallest bag you can find is the 25lb bag. Unfortunately, thats a LOT of fertilizer!! I havn't found anything in my local stores that is of the same formula, but in a less Costco-esque size. If someone does find one, let me know the brand because I would love to find a fert like this as well. I guess you could always split a bag with 10 of your closest orchid growing friends!

[Don Perusse]

A recent article in the AOS Magazine tell of a grower (of many years) and has been awarded over 100 awards for his orchids. His fert. program consist of: 1st wk 20-20-20 plus Pro Cal-mag, 2nd wk 20-20-20 plus STEM, 3rd wk
20-20-20 plus Dip 'N Gro or Dyna-Gro, and the 4th wk only a water flush. It works for him and I think worth a try. I've ordered some STEM & MSU-RO from Ray and will let you know in a future posting. I do think that trace elements are important in plant growth.

[kavanaru]

Originally Posted by isurus79

I know that the Peter's 15-5-15 is the same one that H&R Nurseries uses. I was told, however, that the smallest bag you can find is the 25lb bag. Unfortunately, thats a LOT of fertilizer!! I havn't found anything in my local stores that is of the same formula, but in a less Costco-esque size. If someone does find one, let me know the brand because I would love to find a fert like this as well. I guess you could always split a bag with 10 of your closest orchid growing friends!

hhhmmm... weird... at least in Germany you can get two different bag sizes: 1 Kg (2 lb) and 15 Kg (30lb)... both for 15-5-15 and 13-5-20... I would do some more research and try to find smaller bags in the USA...

[newflasker]

Does anybody have any idea that 15-5-15 and MSU fertilizer have micro-elements such as boron, copper, manganese, ... and what are the percentages? Thanks.

[Dorothy]

This is all about the contents of MSU - Grow In Hydro - Fertilizer

[aerides]

Hello everyone - new member here. Long-time grower on a small scale here. I also read the February Orchids article and have decided to switch to predom. nitrate fertilizer.

Yesterday I spoke with Wayne at Roberts Flower Supply. I gave him the calcium reading in my water from the City Testing Results, which is an average of 5.4m/L, which I think is equivalent to 5.4 PPM (?)

Wayne thought that using MSU pure water formula (his offers 7% calcium and 2% magnesium) would overdo the calciuim. So he recommended the Tap water formula.

I just read on Ray's website that he feels NY water is essentially mineral and nutrient free. We do have great water - my pH reading was 7.1, TDS is 50 and alkalinity is 11.8. But I wanted to double check the discrepancy here. Is 5.4 PPM of calcium essentially negligible?

Frankly, I want to go with the Cal-Mag and to know that it's a better choice than the MSU Pure. Seems about halfway between the tap and the RO. Thanks in advance for your input! This forum seems like the place to be!

[aerides]

Dorothy, that link was so helpful!

[Dorothy]

Anytime

[orchids3]

Have read the contents of this thread and think it is deffinately headed in the right direction as far as Fertilizer goes but question one thing. The pH depends a lot on the water you put the fertilizer in as much as the fertilizer. Found the Green Gro (So called MSU) had to be adjusted with my water - the pH was too low. I love the fertilizer so it is worth it - but the pH of the mix should be tested. It seems unwise to just assume that the pH will be correct for you just because it has been for someone else - the water will make the differance. What is the form of Nitrogen in the Stem, Nitrate, Amonium or Urea? If its the same as the MSU then the only deciding factor should be price. Some will argue that its ok to use any form of N but it is important to some.

[Ray]

Aerides, I'd definitely go with the RO version of the MSU. For one, your tap water is pretty close to "pure" to start with, and if that's not enough reason, just about every serious grower from the NYC area that uses the MSU formulas goes for the RO version.

I think Wayne (a good guy) may have missed a decimal place. If you target 125 ppm N in your solution, you'd need 3.1g fertilizer in a gallon, which is equivalent to 819 mg/kg, and as the MSU RO formula is 8% Ca, that would mean its concentration is about 65 mg/gk or 65 ppm.