# Sources of phosphate other than potassium based phosphate?



## Zapins (Jul 28, 2004)

I need a phosphate based fertilizer that does not contain potassium, any ideas?


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## Zapins (Jul 28, 2004)

Superphosphate has no K in it, but I read this:
Any idea why not with KNO3?



> Although Superphosphate generally mixes well with other products, it is not compatible with the following:
> 
> Potassium Nitrate, Ammonium Nitrate, Mono Ammonium Phosphate (MAP), Cropmaster DAP, Calcium Ammonium Nitrate (CAN) or Urea


Anyone ever use Bone Ash (Calcium Phosphate Tribasic) [Ca3(PO4)2] ?

From: 
http://www.ebay.com/itm/BONE-ASH-3-...818?pt=LH_DefaultDomain_0&hash=item2c62cbf562


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## Phil Edwards (Jan 22, 2004)

I wouldn't recommend using Superphosphate in an aquarium as it's really strong stuff. It'll work great for an emergent grow setup though. I've used bone ash for terrestrial gardening and like it. You'll need to be careful with concentrations though as it too is strong stuff.

What're you needing this for?


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## Zapins (Jul 28, 2004)

I'm planning out a few deficiency symptom experiments and I need to be able to eliminate nutrients one at a time. I need to be able to eliminate potassium from my fert dosing and so I need a source of phosphate that does not contain potassium in order to have all nutrients present except potassium.

By strong stuff what do you mean? Concentrated? Or basic/caustic?


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## Phil Edwards (Jan 22, 2004)

Concentrated. Anything that's used primarily for terrestrial horticulture or hydroponics (if a liquid) is going to be very concentrated compared to what we use in aquaria.


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## old 97 (Jul 25, 2011)

I have been using this (same box) for years. 
http://www.lillymiller.com/labels/LillyMiller/03601200.pdf


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## BruceF (Aug 5, 2011)

How are you measuring the dosage?


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## old 97 (Jul 25, 2011)

http://www.hannainst.com/usa/prods2.cfm?id=045001&ProdCode=HI%20713


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## Zapins (Jul 28, 2004)

Oh no kidding? I found that device the other day is it any good? It seems really well made and cheap to buy.


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## old 97 (Jul 25, 2011)

Zapins said:


> Oh no kidding? ,,,,, is it any good? It seems really well made and cheap to buy.


Ohhh yah, true, I love it. Had it for a year or so.

Don't let the 2.5 ppm max dissuade you. The metre can also be used to test fert. concoctions, by diluting the final solution. If you are expecting around 300 ppm - mix it down with distilled 20:1 before testing. @ ±0.04 ppm you are still further ahead than colour tests.


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## Yo-han (Oct 15, 2010)

I know some color blind people who use it and really like it.

About the phosphate. I think a blend of calcium phosphate and magnesium phosphate (and/or sodiumphosphate although not in high concentrations or you bias the results with sodium toxicity).


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