Dosing with dry ferts.

alip01

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16 Apr 2008
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Hi,

I'm just about to redo my 60L tank. I'm going to be running pressurised CO2 at 30ppm, and 2 x 24W daylight t5 tubes. The substrate is AS Malaya, and I'm going to use PSS and Tropica plant substrate under it.

I'm looking to start dosing using dry fertilisers, and am now wondering what and how much to add. I've emailed the water board for some readings, and they've given me:
Nitrate as NO3 39.6 mg/L
Boron as B 0 mg/L
Iron as Fe 20 ug/L

There are sadly no results for potassium, phosphates or other trace elements. :(

I was thinking of dosing using the EI method, although I've not quite got my head around it yet.

What would you suggest dosing with, how much and how often?

Thanks,
Alistair
 

ceg4048

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Hi Alistair,

I would just scale from the numbers in the article and completely ignore the values given by the water board. 60L is a 15 USG tank which is almost a 20G EI reference tank. You could easily dose the following 20G schedule without any concern. I lifted this baseline schedule from the article:

Sunday – 50% or more Water Change then dose [3/16 teaspoon KNO3] + [1/16 teaspoon KH2PO4] + [½ teaspoon MgSO4]
Monday – 1/16 teaspoon CSM+B
Tuesday - [3/16 teaspoon KNO3] + [1/16 teaspoon KH2PO4] + [½ teaspoon MgSO4]
Wednesday - 1/16 teaspoon CSM+B
Thursday - [3/16 teaspoon KNO3] + [1/16 teaspoon KH2PO4] + [½ teaspoon MgSO4]
Friday – Rest
Saturday - Rest

Scroll a few paragraphs down in that article and it will show you how to make two solutions (a macro and micro) so that you don't have to measure oddball teaspoon values. Let us know if anything is unclear.

After you get the hang of things you can then start to lower the dosages to account for your lower tank volume and the water report.

Alternatively, you can also make up a DIY all in one solution as described by JamesC on his page. http://www.theplantedtank.co.uk/allinone.htm

Whichever formula you choose it's important to read and understand the concepts discussed in the article Dan listed so that you'll understand the ramifications of your choices. :D

Cheers,

Cheers,
 

alip01

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Ahhh, that makes more sense now.

So you basically add enough nutrients to allow the plants to take enough from the water, without running out.

Just so that I'm sure, to make a solution, you'd add a certain amount of the required salts to x amount of water (would it be best to use RO for this?) and then divide the total amount by how many doses you've added. So in theory I could make the same solution for 1 month of doses every 3 days just using 300ml of water, and then only add 25ml per dose?

Otherwise, I think I know roughly what to do now,

Thanks very much,
Alistair
 

ceg4048

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alip01 said:
...Ahhh, that makes more sense now. So you basically add enough nutrients to allow the plants to take enough from the water, without running out.
Yep, go to the head of the class. This simple idea has so many people flummoxed it's unbelievable. :D

alip01 said:
...Just so that I'm sure, to make a solution, you'd add a certain amount of the required salts to x amount of water (would it be best to use RO for this?) and then divide the total amount by how many doses you've added...
You don't need to use RO. I mean, you can... if you have it handy and if you are a stickler for knowing what concentrations you have, but since we only care about not falling below some minimum value, and since we don't care if we go over that value it doesn't matter. That same tap water that has 39 ppm NO3 will do just fine. It just means that your solution will be richer in nitrates and that at some point, to save money by not having to buy lots of nitrate powder you can start to reduce the quantity of KNO3 that you add to the solution.

alip01 said:
...So in theory I could make the same solution for 1 month of doses every 3 days just using 300ml of water, and then only add 25ml per dose?...
Yes, if you reduce the water quantity by 50% the mixture will be twice as rich as if you used 600ml of water. That means you then dose half as much solution each time. You can play with the numbers to suit. Easy as cherry pie. :D


Cheers,
 

alip01

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At last biology and chemistry have been useful :lol:

I'll use tap if it means I don't have to spend as much money, and then make solutions for each powder, so I can follow the schedule's dosing a bit more :D



Thanks very much for you help,
Alistair
 

alip01

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I'm about ready to order the salts, from Garden Direct for the general salts, and AE for the trace mix. Just got a couple more questions.

Firstly, do I need to add anything e.g. extra Iron to the AE trace mix, or is it fine on it's own?

Secondly, just so I know what I'm getting, I need to get Potassium Phosphate, Potassium Nitrate, the trace mix... I have a feeling I'm missing something :rolleyes:

Thanks very much,
Alistair
 

Egmel

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alip01 said:
I'm about ready to order the salts, from Garden Direct for the general salts, and AE for the trace mix. Just got a couple more questions.
Why not get the garden's direct chelated trace mix instead of going to AE, they're very similar and it would save on postage.
Firstly, do I need to add anything e.g. extra Iron to the AE trace mix, or is it fine on it's own?
should be fine as is
Secondly, just so I know what I'm getting, I need to get Potassium Phosphate, Potassium Nitrate, the trace mix... I have a feeling I'm missing something :rolleyes:
Magnesium sulphate, (epsom salts) ebay's probably cheapest for these.
 

alip01

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16 Apr 2008
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Just about to do my order for the plants from AE so that I can rescape on Sunday :D
 
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