It could. There are so many variables and just sitting in a container can add 10 TDS. Getting 526 down to 10 is pretty good I bet. If the membrane and resin are old I would replace them going forward. That is a high TDS to start with so they will wear sooner. For perspective my tap is roughly 35 TDS.
Would either of those buckets be safe to use with 74 & 10 TDS? Will buy new filters for the unit. Wow 35 vs 526- my water is dirty.
Trying to figure out the reef keeper controller...