# Why do we dose micros macros separately?



## Jaap (17 May 2012)

Why do we dose micros on day 1 of EI and macros on day 2? Doesn't that mean that on day 1 the plants will have no available macros to use thus defeating the purpose of EI?


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## CeeJay (17 May 2012)

Hi Jaap

Not sure about this but I think the original concept was possibly to prevent the Iron in the Trace reacting with the Phosphates in the Macro mix, although I have found this not to be the case in the volumes of water we are dealing with.
However, you should find that the strength of the EI macro mix is more than enough to sustain your plants for 2 days at a time (and more). 
I would say it is impossible that the plants in your tank will use up all of the nutrients on the day they are dosed. The reason is this. The original EI experiments ramped up the lighting intensity and duration until no more noticeable difference in daily growth rates were achieved. These values were found to be approx 5-6wpg for 12 hours a day. The EI values were calculated for this growth rate. 
So, if you run any less than 5-6wpg and/or your lights are on for less than 12 hours a day then you will have excess ferts available all the time. I don't know anyone who runs these crazy levels of lighting............actually I do, but I'll mention no names   .
I have messed around with all sorts of dosing regimes with EI values, from dosing Macros and Trace on the same day, to dividing the weekly totals by 7 and dosing small bits every day. I haven't seen a blind bit of difference in the plants. The only one that wasn't too successful was chucking all the weekly ferts in on Day 1 for the whole week   . After about 4 weeks the plants didn't look too happy    so I went back to alternate day dosing.
Other than that if you get your whole weekly dose in the tank at reasonably regular intervals over 7 days, the plants don't seem to mind.
If all of the nutrients are available to the plants all of the time, then we have achieved our goal   .


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## Jaap (18 May 2012)

Yes but still on Day 1 we only have micros and no macros...how do the plants grow on Day 1 without macros? Take into account that we also did a 50% water change the day before and gave the tank the day off...


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## CeeJay (18 May 2012)

Hi Jaap

There will be plenty of ferts left in the 50% of the water you left behind, unless you run supersonic levels of lighting.
We normally dose Macros (NPK) on Day 1. Plants need way more of this than they do Micros (Trace)   .


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## deepak267 (28 May 2012)

I they react with each other if kept together, that's why we keep and dose them separately


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