EI Dosing Calculator

This Excel Chart can be used to calculate the nutrient quantities needed to make a dry fert solution to comply with the EI range of nutrients. The chart can be customized to any regime of water changes and can be used to dose different solutions for every dry fertilizer.

I used fert amounts from the DIY TPN+ solution published on James' site and NO3 data from my water company (some values are still missing). The molecular weights calculation is based on James' dosing calculator.

Big thanks to James, and to Mark from UKAPS for giving me the initial calculation method. As Mark rightly pointed out, this calculation does not include the amounts used by plants and assumes there is no other source of nutrients. It should be used as a guide only.


- Modifiable water change amount and fish tank volume.
- Custom water change and dosing schedule for each day.
- Separate dosing volumes for each nutrient.
- Automatic conversion of gram amounts to teaspoons.
- Dry Fertilizer solubility level check.
- Calculation of dosage impact in ppm for every day.

Download with confidence - No Viruses! (I made it under Mac OSX !) :)

Download Excel File
(Scroll down on page and select "download with filefactory basic".)

If you see anything that could or should be modified, please let me know in the forum, and I'll edit this post accordingly!!!