Cheap dry ferts

parsonsmj

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23 Mar 2008
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11
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Clevedon Somerset
Hi
I have just got the other ingredients for the brew.
However I missed Chelated Trace Elements Mix(500g) - £10.50
I thought the AE trace was all I required!
Have I missed something?
 

ceg4048

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mindscape100 said:
I was also wondering with regards to calculating how much water is in the aquarium.... Do you work out the volume of the tank from the basic dimentions or do you subtract the amout due to the substrate. With my tank that could accound for about 30-40 litres Id imagine. Any thoughts.

Thanks guys
John

Guys,
KH2PO4 is KH2PO4. The references you see to K2O has nothing to do with the chemical formula of the supplied powder. I believe there are certain regulations related to selling fertilizers in that the content must be expressed in terms of a standard reference chemical. In the case of Phosphorus, the content is normally expressed in terms of "equivalent P2O5" and in the case of Potassium the content might be expressed in terms of "equivalent K2O".

It's also a possibility that these are the the original chemical quantities used to produce the KH2PO4. Phosphorous Pentoxide (P2O5) is described as a white, flammable, dangerous, and extremely hygroscopic solid which reacts with water violently to produce Phosphoric acid (H3PO4). Potassium Oxide (K2O) is described as a colorless, hygroscopic crystalline which reacts violently with water producing Potassium Hydroxide (KOH). Since we can dose this powder without any violent reactions, it's safe to assume that neither P2O5 or K2O is present in this powder. Since the combination of [acid + base] always yields a salt it seems a reasonable assumption that the salt KH2PO4 is the result of combining phosphoric acid with the base potassium hydroxide. The data shown on the Garden Direct page therefore is likely the relative quantities of original acid/base used in the production of this salt perhaps as required by law.

If you review the Seachem site for Flourish Phosphorus you will see a similar analysis using these two original chemicals=>http://www.seachem.com/products/product_pages/FlourishPhosphorus.html

The bottom line is this: Buy the Garden Direct KH2PO4 and dose per the instructions in the EI article and don't fret.

Traces are a slightly different story only because trace elements are a mixture of 5 or 6 items so every vendor has a different recipe. As stated the Garden Direct Trace mix is higher in Cu than the AE mix. Sechem Flourish is a different mixture than TPN. No big deal.

Cheers,
 

Martin

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28 Dec 2007
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125
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North Wales
So glad the chemistry boffins on here know what they are talking about, and I can just follow their advice. I was rubbish at chemistry in school and just messed about with the bunsen burners!
 

ceg4048

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Martin said:
So glad the chemistry boffins on here know what they are talking about, and I can just follow their advice. I was rubbish at chemistry in school and just messed about with the bunsen burners!

Hiya Martin,
Yeah, but don't you now wish you had paid more attention in class? I'm just glad you didn't manage to burn your school down.. :lol: :lol: :lol:
 

Martin

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Messages
125
Location
North Wales
Hi Ceg, I'm afraid I was never going to achieve much when it came to science subjects. My path was clearly mapped out from an early age, lets just say I'm more artistic than academic.
 

mindscape100

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Joined
21 Mar 2008
Messages
64
Location
West Yorkshire (huddersfield)
ceg4048 said:
mindscape100 said:
I was also wondering with regards to calculating how much water is in the aquarium.... Do you work out the volume of the tank from the basic dimentions or do you subtract the amout due to the substrate. With my tank that could accound for about 30-40 litres Id imagine. Any thoughts.

Thanks guys
John

Guys,
KH2PO4 is KH2PO4. The references you see to K2O has nothing to do with the chemical formula of the supplied powder. I believe there are certain regulations related to selling fertilizers in that the content must be expressed in terms of a standard reference chemical. In the case of Phosphorus, the content is normally expressed in terms of "equivalent P2O5" and in the case of Potassium the content might be expressed in terms of "equivalent K2O".

It's also a possibility that these are the the original chemical quantities used to produce the KH2PO4. Phosphorous Pentoxide (P2O5) is described as a white, flammable, dangerous, and extremely hygroscopic solid which reacts with water violently to produce Phosphoric acid (H3PO4). Potassium Oxide (K2O) is described as a colorless, hygroscopic crystalline which reacts violently with water producing Potassium Hydroxide (KOH). Since we can dose this powder without any violent reactions, it's safe to assume that neither P2O5 or K2O is present in this powder. Since the combination of [acid + base] always yields a salt it seems a reasonable assumption that the salt KH2PO4 is the result of combining phosphoric acid with the base potassium hydroxide. The data shown on the Garden Direct page therefore is likely the relative quantities of original acid/base used in the production of this salt perhaps as required by law.

If you review the Seachem site for Flourish Phosphorus you will see a similar analysis using these two original chemicals=>http://www.seachem.com/products/product_pages/FlourishPhosphorus.html

The bottom line is this: Buy the Garden Direct KH2PO4 and dose per the instructions in the EI article and don't fret.

Traces are a slightly different story only because trace elements are a mixture of 5 or 6 items so every vendor has a different recipe. As stated the Garden Direct Trace mix is higher in Cu than the AE mix. Sechem Flourish is a different mixture than TPN. No big deal.

Cheers,

Thats sort of what I was trying to say...I dont think I made myself clear with it....anyway Ive ordered most of the stuff from garden direct...apart from the two of the powders which Ive got from the lab ;)
so Ill soon be adding them to the tank and hopefully watching my plants stack themselves!!

John
 

ceg4048

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OK, good. In any case forget about all the gymnastics of subtracting this volume from that volume. Just do your calculations using the size of the tank.

Cheers,
 

tanker

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Joined
23 Feb 2008
Messages
102
Location
Malaysia
Hi guys,
Currently, i'm dosing ADA brigthy k and ADA step 2. i didnt know what is wrong and my weeds are not growing healthily. algae has the upper hand. i have pressurised CO2 and i would say quite high lighting at 8hrs a day.
I'm thinking, the major problem of my dosing now is the lack of N and P. i think potassium is taken care of by dosing Brighty K.

i'm not based in the UK and after reading the stuff on EI dosing, i wanna give it a try. Can you guys tell me what kind of stores, (tesco/pharmacy/whatever) that will sell powders that contain the nutrients as in EI? and also what kind of product that i should be looking for?
thanks
 

mindscape100

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Joined
21 Mar 2008
Messages
64
Location
West Yorkshire (huddersfield)
I think my problem with describing what is contgained with the ferts may also be the fact that Ive had a few beers by the time of postin...(not a good idea) I agree Lisa with what your saying with the epsom salts foe example but like ce
g mentioned the companies may be required to state what went in from the very start. My phd is not in chemistry so I could be far off but that seems logical?? Oh I dont care so long as the plants are happy and theres no floating fishes.....thats all I want!!!
Tell you something though ceg....your a wealth of knowledge thats why I love this site!!

John
 

ceg4048

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tanker said:
Hi guys,
Currently, i'm dosing ADA brigthy k and ADA step 2. i didnt know what is wrong and my weeds are not growing healthily. algae has the upper hand. i have pressurised CO2 and i would say quite high lighting at 8hrs a day.
I'm thinking, the major problem of my dosing now is the lack of N and P. i think potassium is taken care of by dosing Brighty K.

i'm not based in the UK and after reading the stuff on EI dosing, i wanna give it a try. Can you guys tell me what kind of stores, (tesco/pharmacy/whatever) that will sell powders that contain the nutrients as in EI? and also what kind of product that i should be looking for?
thanks

Tanker, where are you again? It might be a good idea to edit your profile to indicate your location. KNO3 an KH2PO4 are strictly agricultural chemicals used by farmers from Canada to Australia. You would find these powders in any agricultural supply establishment and hydroponic gardening supply shops. KNO3 is also used as an explosive with which farmers remove tree stumps to clear the land so you might find it as "Stump Remover" or something like that. If you live in a nation that has a decent agricultural infrastructure you'll likely find these two sold in 50Kg sacks, which is enough to last a lifetime. You could also try pharmacies or laboratory supply. They might not stock these but they will know where to find them. If they do stock them they will be sold there at a higher price that at a farming supply shop.

mindscape, thanks for the compliment and glad you find the site useful. Have another pint for me mate. :D

Cheers,
 

Themuleous

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Joined
6 Jul 2007
Messages
4,124
Location
Aston, Oxfordshire
Placed the order on Saturday, received it today. Doesn't get better than that. 2kg is far more than I had thought, it really is going to last me years!

Well worth remembering for future reference.

Sam
 

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