# So I'm starting ferts tomorrow, help with EI method please!



## dekstr (Oct 30, 2007)

So I'm starting ferts for the first time tomorrow, I've been reading over Tom Barr's EI method articles over and over and over again. Just want to make sure I'm doing it right.

*Dry Fertilizers: *Since Greg Watson's dry ferts cost too much money to ship to Canada, I've found a local store called Homegrown Hydroponics that sells the equivalent chemicals for even cheaper. They sell the chemicals in a package, aptly labeled "six pack" that contains all more than the neccessary chemicals. Basically the hydroponic store noticed lots of aquarists coming into their store demanding the specific PMDD chemicals, so they've developed a package based on PMDD. Since it's not lab quality, it's hard to ensure the purity of each chemical. But it should work the same. I assume the chelated trace element mix (Fe 7%, B 1.3%, Mn 2%, Zn 0.4%, Cu 0.1%, Mo 0.06%) is the equivalent of Plantex CSM + B.

*For my nano 2.5 gallon (high lights, high C02)*, I'm planning to make stock solutions to have easier dosing. Note: I convert his fractions to decimals for consistency.

*Given: Tom Barr mentions that ...* "*You can simply add the dry weights to a solution of water for say 4 weeks, then divide that by say ... Total ferts for 4 weeks(1.5 tsp KNO3 and .25 tsp KH2PO4 etc) + 500 milliliters of water / 28 days = 17mls per day...For a 10 gal....Add 8mls for a 5 gal etc....And so on.*", I can calculate that:

*For trace element mix solution...*
If 1.5 tsp dry KN03 is used for the macronutrient 500 ml water solution, and in a typical 10-20 gallon tank Tom Barr recommends .125 tsp dry KN03 and .03125 tsp dry Trace Elements for each dose, 
then the amount of dry Trace Elements to add into a 500ml water solution is (.03125/.125) = .25 of the amount of KN03. 
Knowing this, .25 of 1.5 tsp = .375 tsp of dry Trace elements to add into a solution of 500ml water.

*For the macro-nutrients, it is fairly straightforward:*
I follow his solution of 1.5 tsp KNO3 + .25 tsp KH2PO4 + 500 ml water to create the macronutrient solution.
Given that Tom Barr also says: 17 ml/day of the macro-nutrient solution --> 10gal.
Then I know that for a 2.5gal, 10 / 2.5 = 4, it is .25 the volume of 10 gal.
Thus 17ml/day divided by 4 = 4.25 mls/day.
Thus 4.25 mls/day of the macro-nutrient solution is enough for --> 2.5 gal.

*My dosing regimen for 2.5 gal:*
Day 1: 50% water change, add GH booster (either SeaChem equillibrium or MgSO4)
Day 2: add 4.25 ml of trace element mix solution
Day 3: add 4.25 ml of macronutrient solution
Day 4: add 4.25 ml of trace element mix solution
Day 5: add 4.25 ml of macronutrient solution
Day 6: add 4.25 ml of trace element mix solution
Day 7: add 4.25 ml of macronutrient solution

*For my 20 gal high (low-medium lights, high C02):*
Day 1: 20-30% water change, add GH booster (either SeaChem equillibrium or MgS04)
Day 2: add under 34 ml of macronutrient solution
Day 3: nothing
Day 4: add under 34 ml of trace element mix solution
Day 5: nothing
Day 6: add under 34 ml of macro nutrient solution
Day 7: nothing
Day 8: 20-30% water change
Day 9: add under 34 ml of trace element mix solution
Day 10: nothing
Day 11: add under 34 ml of macro nutrient solution
Day 12: nothing
Day 13: add under 34 ml of trace element mix solution
Day 14: nothing

Is this right?

Side note: I think I might be going crazy. Doing dry ferts for a 2.5 NANO!?!? WHAT AM I THINKING?? It seems I'm putting too much effort just to save some money. I could easily go the SeaChem Flourish / Trace / Excel method, but that actually costs more money right? Plus I can use the dry ferts for about 30 years if they don't spoil (just kidding).


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## evercl92 (Aug 14, 2006)

Personally, I think the EI method is a bunch of crap. All of the addition of fertilizer amounts is relative to conditions in your tank - plant mass, volume, substrate used, wc schedule, bioload, lighting, etc. All of these are variable from one tank to the next. There is no way that one dosing regimen for EI can be used for consistent results from one tank to the next. There are too many variables. You need to know how much nitrate you plants typically use in a week, so you know how much to add for next week. This involves testing, which is a no-no in EI. Also, doing a 50% wc does not 'reset' those levels to zero. That's absurd. 

(rough) Example:
week 1:
you dose 8
plants use 4
50% wc = 2
total = 2

week 2:
you dose 8
plants use 4
50% wc = 3
total = 3

week 3:
you dose 8
plants use 4
50% wc = 3.5
total = 3.5

granted, it will level off, but it doesn't (and can't) reset to zero. The only way to make it truly effective is to test usage amounts for the first couple months, and adjust your dosing accordingly.


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## hoppycalif (Apr 7, 2005)

An awful lot of people successfully use the EI method to fertilize their tanks, and are pleased with it, so there can be no doubt that it works. I'm sure we don't all have the same plant mass, same light intensity, same CO2 system, etc. The method is based on keeping all of the nutrients non limiting, so only the light determines how fast the plants grow. It has been shown repeatedly that having more nutrients in the water than the plants need does not harm the plants or the fish. And, the weekly big water changes remove the excess of fertilizers if it is building up from overdosing.

No one that I have read anything from says EI is the only way to fertilize, and very few even say it is the absolute best way. What we all say is that it is easy, effective, and non-harmful.

People who prefer to dose only as much as their plants need can chose other methods for fertilizing. Those methods have been found to work also.


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## helgymatt (Sep 12, 2007)

Nicely put!!! I hate testing and I think it is unreliable (at least from my test kits). EI is a blessing for me.


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