Praxair tends to be more expensive for filling than others ;). Find a welding supply company. they typically will be able to help you out and do so for a more reasonable rate. You can also check for a comapny such as Select Sires or ABS - both cattle semen distributors - they typically have routes they follow and will often accommodate small horse breeders.
The only size “filling” tank they offer for rent is huge! How do you do it? Although that may not be a fair question as you undoubtedly will use MUCH more liquid nitrogen:) So maybe I am better off asking how some of your smaller clients do it?
<lol>…Yeah…I suspect even the tank they are offering to rent you is smaller than we use in a week ;).
With that said, it is why I suggested the small 20 liter tank. It fits in the seat of your car fairly easily and can be seat belted into place. It only needs to be filled about every 45 to 60 days ( I’m not comfortable waiting out as long as they say they can hold). And DIP YOUR TANK WEEKLY!!! Also store the tank on a piece of carpet or on a couple blocks of wood NOT on concrete. Concerete will cause the tank to corrode.
Have you ever used these?
http://www.princetoncryo.com/liquid-nitrogen-storage-dewars/doble-series.html
Haven’t had a need to ;). Good luck!