MSU Fertilizer in Semi-Hydro - Orchid Board

Corsetière · #1 09-08-2013, 04:33 PM

I have the Liquid MSU RO/Rain/Tap Water Fertilizer which is 13-3-15. It is recommended at 1oz ( or 2 tablespoons of liquid fertilizer) per gallon of water.

I'm not sure how to calculate how much liquid fertilizer to use for S/H. Could you please help me?

svlair · #2 09-08-2013, 05:26 PM

Go to Orchid Growing Supplies Semi-hydroponics Hydroponics Orchid Books PrimeAgra and click on free info. There you will find a fertilizer calculator to calculate parts per million of nitrogen. Ray recommends 50 ppm nitrogen at each watering.

Ray · #3 09-09-2013, 09:42 AM

1) There is no such thing as an "MSU fertilizer for RO/Rain/Tap Water". There is a formula for pure water (RO, distilled, deionized, rain, snow melt all qualify) sold as "Orchid Special for RO", and there is another for water supplies that do contain dissolved minerals (well water, tap water) sold as "Orchid Special for Well Water".

2) That cannot POSSIBLY be the correct formula for that fertilizer.

The granular MSU fertilizer for RO has that formula, and when you add water to make it a solution, it decreases the weight percentages of the ingredients.

3) That label is entirely misleading, and is illegal.

Corsetière · #4 09-09-2013, 12:18 PM

Interesting. They state that the granular is to be mixed at 1 tsp/gallon and that the liquid ratio of 2 tablespoons/gallon should yield the same amount of nutrients.

So I suppose since we don't know the true percentages of NPK, we are just guessing then? You are suspecting it is more diluted, right? I was thinking I would need to reduce the amount of fertilizer by at least 1/4.

When I put in the numbers for the granular MSU into the calculator I get 172 ppm. And Ray's site say to aim for between 100-150 ppm. So .75 of a teaspoon of the granular would yield 129 ppm. This .75 would equal 1.5 tablespoons(according to the manufacturer's label) in the liquid. Does this sound right, Ray? I guess I will buy granular from now on. Ha ha!

Ray · #5 09-09-2013, 02:16 PM

If they are telling you that two tablespoons per gallon will give the same nutrient level as one teaspoon of the powder, then you would have to weight the teaspoon of powder, then weigh the two tablespoons of liquid to know the true percentages.

However, I think that if you estimate 1/6 (two TBSP = 6 tsp), you'd be in the ballpark, making it roughly a 2-0.5-2.5.

Corsetière · #6 09-09-2013, 03:19 PM

Thanks for taking the time to help me figure this out. So 4 teaspoons/gallon of my liquid MSU should be 106 ppm. This should be acceptable for S/H, right?

greenpassion · #7 10-02-2013, 02:35 PM

I use RO water, and when I purchased my countertop RO system, a container of "Orchid Fertilizer for pure water came with it. I make up gallon jugs of RO water, and when it's feeding day, I use 1/2 tsp in one gallon jug of water. I don't know what ppms mean, and as I said, my water is pre stocked in gallon jugs. My question for Ray I guess, is am I using this stuff right? It's been a few months, and since I started using it, my orchids are really reacting well-new roots and some spiking...???

Ray · #8 10-02-2013, 05:16 PM

Quote:

Originally Posted by Corsetière

Thanks for taking the time to help me figure this out. So 4 teaspoons/gallon of my liquid MSU should be 106 ppm. This should be acceptable for S/H, right?

If you feed approximately weekly, that's fine. If you feed more often, I'd lower the dose.

---------- Post added at 04:16 PM ---------- Previous post was at 04:15 PM ----------

Quote:

Originally Posted by greenpassion

I use RO water, and when I purchased my countertop RO system, a container of "Orchid Fertilizer for pure water came with it. I make up gallon jugs of RO water, and when it's feeding day, I use 1/2 tsp in one gallon jug of water. I don't know what ppms mean, and as I said, my water is pre stocked in gallon jugs. My question for Ray I guess, is am I using this stuff right? It's been a few months, and since I started using it, my orchids are really reacting well-new roots and some spiking...???

1/2 tsp/gal is about 85 ppm N. Again - if you're feding weekly, that's probably OK. More frequently and I'd lower the amount.

As an example, I water 2-3x/week, and I feed at 35 ppm N each time.

Island Girl · #9 10-03-2013, 07:51 PM

I have this same bottle, & I had wondered about this as well, because repotme doesn't give any additional info other than 1oz/Gal... Much less, they dont even tell you what the final solution is in the bottle, is it the standard MSU ratio? Or is it a diluted version? Which makes it very difficult to know how much you are feeding

I will also be buying the granular from now on... Which I had decided to do awhile ago, but it's taken over a year to use up this bottle.... Oh well... ya live, ya learn, I guess.

I've been using it as has been suggested on this thread, but thanks for asking, because I now know that I was on the right track.

Ray · #10 10-04-2013, 12:21 PM

Quote:

Originally Posted by Island Girl

I have this same bottle, & I had wondered about this as well, because repotme doesn't give any additional info other than 1oz/Gal... Much less, they dont even tell you what the final solution is in the bottle, is it the standard MSU ratio? Or is it a diluted version? Which makes it very difficult to know how much you are feeding...

That, by the way, is illegal.

I got a "time out" on another forum for stating that, but a fact is a fact....