# "pre-loading/pre-charging' substrate



## Tattooedfool83 (Jul 7, 2013)

I use Safe T Sorb in all my planted tanks now as its cheap and looks good. I remember reading somewhere about precharging this with ferts. Im in the process of redoing a 20long and would like to give this a try. Can anyone suggest how this can be done?


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## Seattle_Aquarist (Mar 7, 2008)

Hi Tattooedfool83,

When I did my 75 gallon journal (post #10) I mentioned that I 'pre-loaded' the Safe-T-Sorb #7941. I did not pre-load with KNO3 or KH2PO4 but because my tap water is very soft (dKH = 1.0; dGH = 3.0) I did pre-load with Ca and Mg.

First I screened the dry Safe-T-Sorb to remove the dust and 'fines'. I put the dry, screened substrate in a bucket. In another bucket I mixed up my pre-charge solution using equal amounts of CaCl2 and MgSO4 which allowed me to maintain the approximately 3:1 ratio of Ca to Mg. I added the solution to the dry substrate and soaked each batch for about 15 minutes until the bubbles stopped. I stirred up the substrate a couple of times during the process to insure the solution got to all the substrate.

The two reasons I did not pre-load KNO3 or KH2PO4 are: 1) I like to know exactly how much of those nutrients I am making available to my plants and 2) I did not want to make excessive nutrients available during the beginning of the nitrogen cycle when algae issues seem to be the most prevalent.

Here is the 75 gallon 4 months after filling and planting


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## Tattooedfool83 (Jul 7, 2013)

Awesome Seattle, i was hoping u would respond as i asked that question on your thread but couldnt remember what the thread was called. Thank you so much


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