# EI Dosing Math Check



## ianmartyn (Nov 1, 2007)

I'm over thinking things and hope that no one pokes fun at the fact that I may have this wrong or am even asking this question.

I am going to try and follow the Estimative Index dosing schedule. Rather than adding the ferts directly to the tank I am going to make up a stock solution with distilled water. I am going to add NO3 and KH2P04 to the *same solution*.

The target range for NO3 is 5ppm and KH2P04 is 1ppm, three times a week.

So, I plan to add 20ml of the stock solution three times a week to my *85 gallon* tank. My math is below, can anyone verify!

Stock Solution - 500 ml

If I add 66 grams of NO3, every 1 ml will add 0.25 ppm. Therefore, 20 ml should raise N03 to 5 ppm.

If I add 12 grams of KH2P04, every 1 ml will add 0.05 ppm. Therefore, 20 ml should raise KH2P04 to 1ppm.

I plan to use Flourish to dose micro nutrients.

Does this all make sense?

Any help on the matter would be greatly appreciated.


----------



## Darkblade48 (Jan 28, 2008)

Mathematically wise, you are correct.

Principally, though, you have several misunderstandings.

The method you are using to dose is not EI dosing. EI dosing is based on the fact that you don't need to have these complicated calculations, and that you are not calculating how much of an increase in ppm of some nutrient you are adding per dose.

EI is based on the simple principle of adding more nutrients than the plants need at any given time.

The method you are using more closely resembles PPS or PPS-Pro.

Finally, note that the formula for potassium dihydrogen phosphate is KH2PO4 and not P04 (a capital 'oh' not a 'zero').


----------



## ianmartyn (Nov 1, 2007)

*Thanks for the feedback*

I am trying to follow EI as close as possible, so, I see what you're saying. I shouldn't be trying to hit ppm right on, I should be supplying these nutrients in excess each week, each time I dose them. I made the mistake of using the recommended ppm from a nutrient calculator, which recommends lower doses than the EI method.

I know I shouldn't be trying to hit a number right on, but generally I am still aiming for a certain nutrient level in the water?


----------



## Darkblade48 (Jan 28, 2008)

The nutrient concentrations that you have listed are a bit low for EI dosing as well.

I believe EI dosing usually aims for NO3 to be at least 10-15 ppm, while phosphates usually are around 2 ppm.

Take a look at the lengthy article that Tom Barr wrote regarding this:

http://www.barrreport.com/showthread.php/62-The-Estimative-Index-of-Dosing-or-No-Need-for-Test-Kits

By dosing only 5 ppm, you are risking that your plants will run out of nutrients, as 5 ppm is not a lot at all.


----------



## ianmartyn (Nov 1, 2007)

*Thanks again,*

I added more macros to my stock solution last night, so hopefully I'll be supplying nutrients in abundance now.

I'm going to do my 50% water change tomorrow and start dosing, so wish me luck!

Ian


----------



## Darkblade48 (Jan 28, 2008)

Don't forget that any changes you are looking for will take approximately 2-3 weeks at the very least before they manifest themselves.


----------



## ianmartyn (Nov 1, 2007)

*My tanks is only a week old now so I'm still touch and go*

The HC seems like it's starting to send off shoots and the grasses and definitely growing as well.

Hopefully, they fill in quickly to fight off any algae, that is probably right around the corner.

The only thing that I'm not sure about right now is the photo period. My lights are on for 9 hours a day, 4 T5HO bulbs for 216 watts. Should I be throttling that down until my plants get well established?


----------



## Darkblade48 (Jan 28, 2008)

You will only need 2 of those T5HO lights to get high lighting; 4 bulbs is asking for trouble.

In addition, a photoperiod of 8 hours or so will probably be best; you may have to actually cut it down to 6, depending on your plants.


----------



## ianmartyn (Nov 1, 2007)

*Ya, I was thinking with all four bulbs on I was cruising towards algae ville*

I am trying to get a carpet of HC going. I picked up a few nice pots last week at the Menagerie. I also have some Dwarf Hairgrass, Eleocharis Vivipara and some Pygmy Chainsword. I'm trying to go for a Iwagumi style.

I have dabbled in low light tanks before, but saw some incredible aquariums while in Japan this summer and have caught the bug. I didn't make it up to see Amano's studio but saw some stunning tanks.

I did my first 50% water change, then dosed my macros today. The aquarium is pearling like mad now. 

I will turn my timer to 8 hours and turn off two bulbs until I get things growing in nicely. Or maybe I could set the other two bulbs to come on for a short burst for a couple hours?

Do you add anything to raise the GH like Tom Barr suggests?


----------



## Darkblade48 (Jan 28, 2008)

Having two bulbs is fine. If you really want, you could have a short 2 hour noon burst with all 4 bulbs, but it is not necessary.

With the water as hard as it is in Toronto (and most of Ontario), it is not necessary to add the gH booster as according to EI dosing.


----------

