Single Ei Mixture, Multiple Tanks?

nodima

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Dec 4, 2018
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The plant bug has spread a bit for me, and there are now 4 tanks in my house with plants. I’ve got my 90 pretty well dialed in, using EI, and am happy with the growth rates and the tanks health. I’ve been mixing the fertilizers in a 500ml container and dosing according to Rotala Butterfly.

I’d like to expand my fertilizer regimens to the other tanks but am not sure how best to proceed. Chemistry was never a strong suit of mine, and what is simple and clear to others just is not to me.

The other tanks are 125gals, 20gals, and 6 gals. Is my best route to make up separate EI solutions for each tank? Is there a way I can make a single solution and change the dosing volume for each tank? Something along the lines of 1x for the 6gal, 3x for the 20, and 18x for the 125? How would I go about determining the right levels of each dry fert for each tank?

Thinking I’d mix the solution based on the 20gal tank, using a 500ml container and dosing 30ml for the 20. This would say that the 6gal tank would get 1/6 of 30ml or 5ml solution, and the 125 would get 120ml.

Am I overthinking/complicating this?
 

nodima

New Member
Dec 4, 2018
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Some additional searches found that others are doing the following:

Add up the total water volume for the tanks. In my case 151gals.

From the EI tables, take the 75g version and double it.

Then divide the mixture volume (500ml by the tank volume) for me, 3.31ml per gal. Since EI is dosed 3x per week, divide by 3 so 1.1ml per gallon, 3x a week. The 6 will get 5ml, the 20 will get 20ml and the 125 will get 120. These amounts are either marked on my vessel or multiple fills can add up to them.

Anything seem off with this approach?
 

toads74

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Jun 3, 2013
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Sounds like a good approach. My method i use is to calculate the solution based on x ppm per 10g (3tsp of solution dosed). So the 10g got 3tsp, 20g gets 6tsp. If say the smaller tank needs more, just bump it to 4 tsp. I scale it for an easily measured quantity. Don’t be afraid to use larger dosing volumes (keeping the same ppm). You can always mix it for 90ml for the 90, 20ml, etc using a graduated measuring cup, or syringe might be helpful for the 6g.