Production Techniques and Chemistry > Colloidal Silver Production

1st Attempt of Colloidal Silver



Here's my 1st attempt at making Colloidal Silver (20ppm)

Reducing Agent: equal parts Light Karo & Distilled Water mixed
Electrolyte: 12.4gr Sodium Carbonate (washing soda) mixed in 100ml distilled water

*I didn't bake the Sodium Carbonate - is that ok?

First I added 1L distilled water & 20 drops of electrolyte to the beaker - magnetic stirrer activated.
1 inch wide vortex
Temperature set to 65 degrees celcius

Inserted 2x 14g silver wire 99.99% electrodes.
Positive was inserted around 5 inches. Negative 1cm deep.

Going for 30min @ 10mA for 20ppm

I started off with my lab power supply set to 27v & found it difficult to maintain a solid 10mA, was flickering between 0.01amps & 0.02 amps  (10mA and 20mA)
(It's difficult to accurately get the milliamp reading on my lab power supply as the digital read out shows 0.01 amps not milliamps.)
This setting was for 5 minutes.

Then changed the voltage to 13.5 and it maintained a solid 0.01 amps so I ran this for 25min.

After the 30min total I turned the power supply off, removed electrodes and added the Karo/distilled water solution (4 drops)
The finished product changed colour from clear to yellow
The small cup next to my beaker is 35ppm Colloidal Silver I purchased from ebay just for comparison.

Is it important to have more accuracy with my milliamp setting or is what I did ok?

Also besides the blackening on the silver wires there wasn't any build up. Is that ok?

(both silver wires have black on them beacause I swapped them 5 minutes into the process)

Is my end product safe to use?

Many thanks,


Color looks good. The trouble with these cheaper (or higher power) lab PSUs is that they don't do the lower end very well, like you noticed. If the two lowest settings are 10 mA and 20 mA, you would have to check with a multimeter to make sure these values are roughly correct and don't fluctuate too much.

For higher than 20 PPM, you will find that 10 or 20 mA is also quite a lot and may be too much for a timely reduction. Even with 5 mA constant current I notice that it's too fast occasionally, depending on temperature and reduction agent.

As SaltyCornflakes said, the colour looks good and it's best to put a sensitive amp meter in line so you can see the exact milliamps. If your PS is bopping between 0.01 and 0.2 then it's rounding the number which is hovering around 0.015 amps. Still, I would not trust the accuracy and get a good meter put in line.

Swapping the electrodes is not something recommended here as Kephra explained. And if you don't have a problem getting polarities mixed up, it's recommended to use a silver anode (+) and copper cathode (-). So that's the black negative wire to the copper cathode and the red positive wire to the silver anode. I just use a bit of household electrical wire with the insulation stripped off for the cathode.

It doesn't matter if your voltage fluctuates, just as long as it stays above 10V. Keeping the current as steady as possible enables you to accurately calculate the PPM.

The blackening is normal and can be either wiped off or flame cleaned with a propane torch or natural gas stove burner. The black will go back to white. Just be careful not to melt your electrodes.

You don't need to bake the sodium carbonate. Sodium bicarbonate needs to be baked to create sodium carbonate.

The product you made looks (and sounds) good. I would use it.

Thanks Neofizz & SaltyCornflakes for the information.
I will look into an amp meter and use a copper cathode next time. Its important I can calculate 20ppm as I want to add 100ml Colloidal Silver to 900ml of colloidal gold and improve the shelf life. I recently made 2 batches of CG that turned out great via Kephras instruction using electrolysis.

Best regards

Purchased a more expensive lab ps that gives better accuracy at the low end. Great results  :)


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