OK, I got some decent prints using inkjet. Some learnings about ink being "waterproof". It isn't actually, it's dependent on what you print on. Kind of like juice or something. It will wipe off some things but locks into and stains a fabric permanently. Same concept.
So, long story short I have some very nice, bold tags printed that do not "run" when placed under a running faucet. As they are tucked away under the tank they should hold up pretty well from a UV degradation perspective. There are sprays out there for UV protection on vinyl sheets however they add a gloss or sheen to the label. I'll get sending ASAP. Sorry for the delay. If anyone would like the file to make your own please let me know. It's in MS Word. You have to use Word, not a free program to open it or it will change the formatting and it will not look "correct".