Maybe an advanced person can answer this.
I have a smileo, that I have used quite a bit and cleaned a couple of times using only hot water and taryn spin method.
After the third cleaning, it was really hard to draw on through a newly charged Zeus. But instead of throwing it away, I got out an old passthrough and plugged it into the adapter, placed the smileo on it and it drew much better.
Both were tested on a meter and both were giving 5v, so why is the old carto working better on the passthrough?