Just a few observations on the blue foam stirrer mod. First, thanks to Pete54 for refining this and all others who had a part in developing it.
Some people had questions about how this works and why. My take is that not much of the liquid wicks through the straw, since the liquid is thick and the foam is tightly compressed inside the straw.
The straw is there to provide a support for the small amount of foam and to back up the foam as it contacts the atomizer. We've all seen how much the media compresses when you have a cart full of foam. The foam is pushed back by the atty and soon doesn't make sufficient contact to wet the wick on the bridge. Then, you get little vapor and a hot atty.
The space created by the straw allows pure liquid in the cart to wet the wick when you lay the 510 down or turn it in a direction where the liquid can run down and wet the foam. The stock filler that comes in the cart is not efficient in wicking the liquid up to the the end of the cart and you end up with a dry spot on the atty end and can see that there is liquid on the bottom of the media when you pull it out with tweezers. So, we end up dropping a few drops on the dry end while the other end is still wet!
If you are getting too little vapor the foam is probably too tight and is compressed too much to absorb the juice.. If you are getting liquid through the mouthpiece or leaking between the cart and the atty, the foam is too loose to block liquid from running past and into the atty or the foam is sticking out of the cart and getting into the airway. The foam should not protrude past the end of the cart after filling. It's better to have the foam just under the end than hanging out! The air that comes out of the mouthpiece passes by the atty element and into two little slots on the side of the cart. If you get juice on this part, it will eventually end up in your mouth!
Some have had trouble determining what kind of foam to buy. Here's a link with a good picture of the product we are using.
Marineland Magnum Foam Sleeve "Rite-Size U" 3pk.