Yes I did resize them to the same size, 500 pixels being more or less randomly chosen, while I was preparing a few more to add. That occurred after I decided that the RC photography forum would be a more appropriate location for a thread relating to tank pictures. That conclusion was reached when recalling that when I asked fellow reefers whether or not they used a macro lens, the thread was promptly moved to the off topic area. They also have quite a few very serious and very good, tank photographers there, making it a useful venue to receive technical feedback, although this is never guaranteed.
RC do have some general guidelines but still seem quite happy to accept and display full tank shots at quite large sizes, up to 1000pixels being quite common.
Steve