I am using that tank now and it seems to be working great ...... BUT ...... I had a problem getting the top off to fill it (seal is tight) and someone said to just slide the carto down till you could slide a needle in around the top and fill. I've done that 2-3 times, and now the tank turns on the carto so easily I can't get it off my battery. The tank was spinning but not the cart.
I had to get something to grab the top of the carto to turn it ..... am I missing something?
Hold it from the bottom black part to twist off and not the clear tank part. Get used to doing it that way and it will come right off. Also do not tighten it too much, it only needs to make contact.
I have had zero problems with my carto tanks. The way I fill is to pull on the bottom part of the carto until it clears the top seal, remove the top, push the carto up again until it is flush at the bottom and fill with a bottle. Once filled, and not all the way to the top - leave a little space for air, push the top seal over the carto and done. I put the carto bottom on a surface so it will not push down while putting on the top part. Takes about 30 seconds and is easy.
I have 2 tanks, one I enlarged the stock hole with a nail and the other left it alone. Both work great.