Mueller Show Cattle
Well-known member
I have an older MVE 20/20 tank, probably 10 years old (20 liter tank) that I have been using for almost 5 years now, bought it used but is still working great, I have been refilling it about every 4 months (120 days or so) to be on the safe side. Well I forgot about it for a little and almost went 150 days on this last refill this morning. I measured the liquid nitrogen level before I had it filled and it showed 9MM on the MVE measure stick. That concerned me a little as it is normally around 15 MM when I have it filled but I also went about 30 days longer on accident. It did not have much vapor coming out of it when I opened it this morning to measure it, but it was also 0 degrees outside in the shop where I store the tank, I store it on a wood pallet in a dark corner of the shop away from sun light. I don't have any manual or anything on the tank cause I bought it used years ago. So I figured I would ask, I know you can't run the tank dry or you will kill all the semen/embryos. For anyone that has been using them awhile or knows what is the recommended level to not go below to keep the semen safe from thawing? Cause I have a couple canisters that have full canes with semen in the upper goblet, so I expect that semen to be above the level nitrogen level when the tank starts getting lower. So I am just trying to find out a recommended level on when you are suppose to refill it, I would guess that even at 9MM still in the tank that it should have been plenty cold enough to keep the semen frozen in the upper goblets in those canes? We don't have anyone that comes around here to fill tanks on a schedule that I am aware of, so I just am trying to keep track of it and get it filled every 4 months, this 9MM is the lowest it has ever been since I have owned the tank. So any advice or information is appreciated. Thanks