FeedMe Fertilizer

[Alan Sailer]

After getting some information about ca/Mg supplements I did some searching and decided to buy FeedMe fertilizer for use with RO/rain water ie low dissolved solids.

I received the stuff yesterday and dissolved 1 teaspoon into a gallon of my RO water which has a TDS of about fifty.

Checking the pH after the mixing I was surprised to see a reading of 3.8 which seems way too acidic. I could use lime to raise the pH but it seems strange that I would need to do this. The baseline pH of the RO water is 7.

Am I over measuring this or is there a problem? In the past I have been using DynaGrow and it does not change pH at all. But is has very low levels of Ca/Mg.

[Roberta]

I would distrust your pH meter... do you have pH paper? it may not give you the numbers after the decimal point, but more accurate than an inexpensive meter especially if not calibrated (multi-point).

[Alan Sailer]

Roberta,

The meter is a freshly calibrated Apera PH60 pH meter.
It uses three calibration standards 4,7 and 10pH.

I guess I could cross check it with pH paper but I bought it to avoid using all those darn strips..

Cheers.

[Roberta]

What is the formula of the FeedMe fertilizer? Phosphorus (middle number) should be lower than the other numbers... it gets added to lower pH in water that is hard. So a pure-water formula shouldn't have much. The MSU fertilizer Cal-Mag formulation that I use with my RO water is 13-3-15, calcium 8% and magneium 2% . (Based on Ray's observations with K-lite, it probably doesn't need the potassium but doesn't seem to hurt anything) When I mix it up 1/2 teaspoon per gallon, I get pH around 5.5. The RO water is about 7, but it has no buffering capacity so the fertilizer is "in charge" - the starting pH of the water has no influence at all.

[Alan Sailer]

The FeedMe! is 15-3-15 8Ca 2Mg.

Good information about your pH numbers. I'll try again tonight (maybe, it's so hot!) and use pH paper and the meter to compare. Your RO water is the same starting point as mine. It's just my end point is much lower. Your final is perfect...

So you are mixing half strength (1/2 t vs 1t)?

Cheers.

[Roberta]

Originally Posted by Alan Sailer

The FeedMe! is 15-3-15 8Ca 2Mg.

Good information about your pH numbers. I'll try again tonight (maybe, it's so hot!) and use pH paper and the meter to compare. Your RO water is the same starting point as mine. It's just my end point is much lower. Your final is perfect...

So you are mixing half strength (1/2 t vs 1t)?

Cheers.

Yes, I do 1/2 teaspoon per gallon. For heavy feeders like Catasetinae during growth, and Cymbidims in general, I boost fertilizer with time release. But use a light hand with everything else. I still wonder what could be driving the pH so low (if it really is) I'd be really interested in whether the paper corroborates the meter or not.

---------- Post added at 02:37 PM ---------- Previous post was at 01:58 PM ----------

If the pH paper gives the same result, I wonder if there was a mix-up in labeling such that you really ended up with the well water formula. Yours is blue, right? That would be the correct color... the well water formula is pink, I believe.

[Alan Sailer]

Roberta,

Here is the info. Trying to be as accurate as possible.

I used one quart of RO water. The pH strip said 7 and the meter said 6.73.

I added 1/4t of FeedMe!. The pH strip said 5.0 and the meter said 4.4. I dipped the meter in the 4pH calibration solution and it said 4.02. The pH strip said 4.

The only difference from my earlier measurement was 3.75 vs 4.4pH.

I noticed one detail. My FeedMe! is neither blue nor pink.
It is mostly white with a sprinkling of Green pellets. The green pellets are larger than the rest of the stuff. So like brazil nuts in a mixed nut can they float to the top.

Maybe the green pellets are high acid? If so, maybe my first scoop had more of the green pellets than this latest scoop. In any case, the result is far too acid for my taste.

In any case, since my fertilizer is neither blue or pink it is a different breed than normal FeedMe!

I am going to call up the company and find out what is going on...

Cheers.

[Roberta]

Originally Posted by Alan Sailer

It is mostly white with a sprinkling of Green pellets. The green pellets are larger than the rest of the stuff. So like brazil nuts in a mixed nut can they float to the top.

Maybe the green pellets are high acid? If so, maybe my first scoop had more of the green pellets than this latest scoop. In any case, the result is far too acid for my taste.

In any case, since my fertilizer is neither blue or pink it is a different breed than normal FeedMe!

I am going to call up the company and find out what is going on...

Cheers.

My MSU fert when completely dry is more yellowish. As soon as it's exposed to air it picks up moisture and I end up with little blue-green balls. The stuff is VERY hygroscopic. I bought a 25 lb bag from SVO several years ago, keep it tightly closed with a binder clip, inside a 5 gallon bucket with tight fitting lid. Then I transfer a relatively small amount to a wide-mouth shallow jar. The original stuff stays quite dry. What I put in the jar picks up the moisture to form the little balls within days... that amount gets used up in 4 or 5 sessions. Otherwise it cakes. (That original bag may last for the rest of my life...) Worth a call to rePotme to be sure that there wasn't some problem with the formulation.

[Alan Sailer]

Yes. I will try calling up the seller and see if they know what is going on.

I hate wasting stuff but I may just toss it and try another brand. What is the maker of the stuff that you use?

Cheers.

[Dimples]

Before you toss it, have a look at Ray’s website. He has instructions on there to make a concentrated stock solution so you don’t run into the problem of scooping up uneven amounts of the different fertilizer components. If you dilute the entire batch it should solve your problem, assuming the fertilizer formula is correct. If it doesn’t fix it, you were going to toss it anyway. You can use it on outdoor landscape plants. They won’t care that much.