How much RO water can you store before water test? Might not be a bad idea to have an LFS have some on tap, so to speak for you to get up and running. if you can store a lot, its gonna be a lot of bucket carrying and at least for me tough lifting 5G of water at a time over the tank rim. (damn this 8' titaniam plate and screws in my arm, still healing). So in the future, worth investing in a pump. bring it in in buckets and then, pump it into tank while you get the next batch ready.
Just my 2 pence worth.