How does heating the solution remove the need for an aerator like a bubble stone?
I would say at this point, if you don't stir every half hour, it doesn't. Mine grew flat silver crystals and shorted the electrode for a while. Increased the current dramatically. A bubble stone would have split those up.
However, I started with 4ppm bottled water and the electrode went crazy dissolving a yellow mess. I had to remember that wasn't distilled and switch to 0ppm water, which did not show excessive dissolving at start.
I doubt the stone doesn't contribute dissolved solids. However, if you're making a lot, mabve that's better than nothing.
So: bubble stone stops bridges from forming, and also keeps small particles evenly dispersed (so they aren't as likely to get bigger). Heater keeps small particles apart also (heat means the molecules are bumping around faster), but it's insufficient to prevent formation of silver on the top surface, bridging the electrodes and messing up current flow.
If you're only making 150ml, it only takes about 5 hours at the low rate of 1 milliamp. You could speed that up greatly in 150ml, I made some in 40 minutes at 30V.
How does anyone not believe that the electordes break down? That's how the silver gets into the water! *facepalm
Well, if you do a REALLY good job, it's maybe almost as minimal as they claim. If I hadn't goofed at the end of this batch, the amount of fuzz generated was super tiny.
Here's some stats on my last try, but I was cooking christmas food and got interrupted a bunch. Even so, it's interesting because it sort of defies some of the wisdom out there.
I was trying to reproducably (so others could copy the setup without having to measure) produce 150mL (fills my little sprayer) of colloidal that would have a decent shelf life (small particles).
At 4.0 volts, less than 1 mA flowed with the electrodes spaced 1/2-3/4" inch apart. Because the beaker was short, I bent the electrodes in half, thus keeping the same surface area exposure to water that I had in the large mason jar. Needless to say, with the ratio now at 10 to 1 surface area of silver, the process goes very fast.
I heated it hoping that would knock the silver around to keep the particles small. It indeed have done that, I got no fuzz whatsoever on the bottom of the beaker. Only slight on the electrodes. So i do believe in heating. But it wasn't enough to stop silver crystals from forming sheets (small patches) of silver on the top, which eventually shorted out the electrodes and kept me from finishing measuring.
Water temp 135F. Current flow at 4V remained from <1mA to <2mA, gradually rising over time. TDS raises 4-8ppm per hour. Since TDS is nonsense here, it's not surprising it varies that much. If you let it raise to 15 for example, and let it sit, it'll drop back to 11.
At a TDS of 7, a laser is visible in the darm. It's not until TDS is > 20 that you can see the laser even with room lights on.
After 20, I goofed and walked away, so a sheet of silver bridged the electrodes. Current flow when I noticed that was erattic, and floating around 20mA. Stirring reduced it to back down below 2mA. When I discovered that had happened, the solution was a very slightly detectable yellow, and the laser shows in the light.
So it's done, but maybe not high quality due to the uncontrolled current at the end. I need it, so I'll use it, but I'll redo the experiment again.
Knowing 4V is good for the whole time if volume is low, I'll try it at the voltage of a single 9V battery, but with my power supply so I can monitor the current.
What's the point of all this: To make some solution that lasts, but to make it fast enough that you don't really need to save it, with minimal electrode loss.
As for seeds, I get 1000 per autoflower if I spray one and dump that pollen on the other. And I get a few S1 seeds from the one sprayed, so I can repeat that.
I'm doing a Northern Lights, an AK47, and an Amnesia Haze right now.