# KH/GH has gone crazy...



## The Abbott (8 Nov 2010)

Hi all, i'm 3 weeks in to my EI dosing - 240 ltr tank so a 125 ltr change every sunday, and am following the dosing as described on James' instructions. I have to be honest I have not noticed any change in growth/ general healthy appearance of plants at all, which is frustrating. Anyway back to my parameters.....
This week my kh/gh have gone crazy -  I changed water as normal then after an hour tested for kh/gh as normal - my reading were KH 9 and GH 11 !!!! and this is with RO water, Ive since tested my RO unit and its fine so what the hell can cause this??? The only thing that I added before testing were my dry ferts, again, as normal....

I'm baffled, any ideas????

Rich


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## dw1305 (8 Nov 2010)

Hi all,


> The only thing that I added before testing were my dry ferts, again, as normal.


 As it is R.O. the only source of the ions is the fertiliser addition. Calcium and magnesium (2+) ions will raise the GH and any carbonate or bi-carbonate ions the KH. If the GH/KH are higher than after your first week of EI, it is because not all of the fertiliser from the first addtion have been used by the plants. I don't use EI, but the idea of the dosing and water change is that the plants are never deficient of any macro or micro elements and the water change re-sets the water to a known starting point. 

Do you have a conductivity meter? if you do you can test baseline conductivity (100% R.O. with 1 weeks EI dosage) and this will give you a datum. If the conductivity rises over time, you either need to do a larger water change or lower your dosing. I'm sure many people will tell you not too worry about the test results or to just stop testing. The other variables are plant growth, as your biomass increases it will use more of the fertiliser addition, and as you prune you will bt exporting your NPK, Mg etc. & possibly your substrate if it has a large CEC.

cheers Darrel


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## gabriel.basso (11 Nov 2010)

Hi Rich

As Darrel said, probably the intake rate of your plants is lower than the nutrients available (main principle of EI!) and it is causing the GH/KH to raise... but, besides that, I woudnt rely too much on test kits... Recently I've almost gone crazy testing a homemade 4dkh reference solution for a drop checker. Had 2 different KH test kits (sera and hagen) and 2 different results. These tests can be very inaccurate. 

cheers
Gabriel


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