@Kashka
I relatively new to the MMS/CDS world but started with making my own batches of CDS. I made about 6 to 8 batches using three different recipes. Used Andreas' recipe for the first batch but found it too time consuming (24 to 48 hours to complete). Then I started using CLO2's Quick method using one infusion in 3 hours time . This search link from this forum has many items about making Quick CDS. These are posts by CLO2 about using the Quick CDS method.
mmsforum.io/goto/search?query=quick%20CDS&searchuser=CLO2&exactname=1&searchdate=all&searchatdate=03/25/2022&childforums=1
This link includes PDF's you can download with the instructions.
As far as testing I use the LaMotte Insta-test #3002 test stripes. With the 0 to 500 range. From my experience your 1 to 9 ratio is way to tight.
I use the 1 to 30 ratio. So that 29 ml of non tape water (I use either reverse osmosis or bottled alkaline water) and 1 ml of your CDS concentrate. If the colour of my testing strip matches up with 100 on the 0 to 500 range I have 3,000 PPM CDS. So 100 x 30 = 3,000.
Even better is the 1 to 60 range. So 59 ml of non tape water and 1 ml of CDS concentrate. This time I want my the colour on my test strip to match with the 50 on the 0 to 500 range to give me 3,000 PPM CDS. So 50 x 60 = 3,000.
mmsforum.io/goto/search?query=Test%20strips&searchuser=CLO2&exactname=1&searchdate=all&searchatdate=03/25/2022&childforums=1
This link also has a PDF explaining how to use test strips to make sure you are getting 3,000 PPM CDS.
Test strips turning brown doesn't sound good at all.
Jim