Now it makes sense... you've been using diluted sea water to top-up and change water for the past 2 years... if you can maintain a tank for 2 years within the range of 1.023 to 1.025... perhaps your method works (although a bit uncommon). But on the other hand, by diluting the natural sea water... you will wipe out some if not all the beneficial bacterias that come with the sea water... hence sounds like defeating the purpose... unless of course you choose natural sea water out of convenience sake