i don't own a mini protank, but do have a few original protanks.
straight from the box, one of mine would not hold
juice. it kept leaking around the bottom, between the glass and the bottom ring. i tested its fluid/airtightness by removing the base and emptying, putting the protank open-bottom-side against the palm of my hand, and sucking on the drip tip to create vacuum. of course, it let in air, which told me the glue had failed. i did the same to my other protank, and it did produce a vacuum, so that one was good.
i didn't want to try to send it back for exchange/refund, as i bought it on a special sale which clearly said 'no refunds/exchanges'. as it was defective from the start, i probably could have fought that, but it took two weeks to reach me already, due to the USPS sending it on an extended tour of the US before shipping back to the sender. so i decided to try a fix...
for two days, i soaked the bottom half of the protank (with base removed, of course), in a shotglass of nail polish remover (i didn't have any straight acetone), filled just above the bottom metal ring, maybe 1/3 to 1/2 way up the glass portion of the
tank. i had to refill maybe once or twice due to the polish remover evaporating.
when i removed it from the remover, it was fairly easy to pull the ring from the glass, as the remover softened the factory glue up nicely. i then soaked both the ring and the bottom part of the glass in fresh remover for another day, to soften the glue even further. once it was nice and soft, i used scrubby pads and paper towels to remove the glue. some stubborn glue was scraped off carefully with a knife. after all the glue was off, i gave another wipe down with a towel soaked in remover to get off any remnants, and washed thoroughly with warm soapy water, and a clean water rinse.
to reassemble, i used a thin coat of 100% silicone clear aquarium adhesive/caulk. i believe any clear 100% silicone caulk could be used, but i had it on hand, and it said on the tube it was non-reactive and safe for fish, so i figured it would be fine with any juices. i placed a thin coat both on the inside of the metal ring and the outside bottom of the tank glass, pushed the pieces together and gave a slight twist to make sure the glue coated all surfaces.
i let it dry/cure for a day or two. of course, when i put the pieces back together, some excess caulk had seeped out of the visible joints, both inside and out. if this happens, DO NOT WIPE IT UP right away, especially if it seeps thru the inside joint. if you try to clean it while still wet, it will just smear around and be a bigger problem (don't ask me how i know... lol). just let any caulk that oozed out set up in place, and after a day or two, after all is dry and cured, go over the globs of caulk with an xacto knife or other small sharp blade, and trim it off.
so far, after 2 months, my repaired protank works like a champ. no bad taste, no ill effects from the caulk.
but... it might just be easier for you to buy a new one. or get a mini protank 2, which i guess eliminates the glue altogether...
