Not sure on the hundreds of gallons every couple of days. My backyard pool looses about 2" of water a month on a 24' diameter pool. That is a total of 113 cubic ft of water which turns out to 845 gallons per month. Or about 30 gallons a day.
A 24' pools hols 18050 gallons of water and in Lubbock Texas in the summer at about 96-100 degrees the water stay at about 76-80 degrees.
($3500 for pool) ($30 increase in water bill to fill, $5 a month to top off and water changes) ($30 for salt to make 200
gal, $700 a month for 25% once a month) ($2700 for salt to start)
with 2 pool pump systems for flow you would have plenty of flow. ($300 for extra pump)
Sun would provide plenty of light for anthing in the pool especailly if just having
fowlr system. (free)
27075 lbs of live rock for 1.5 lbs per gallon ($160,000 from
lr.com, or $23,000 from hirocks.com)
heater for winter time. ($800 per unit, two needed, $1600)
skimmer would be a PITA!!! ($700???)
Plexi panel for viewing woult need to be 1" thick. ($500) ($200 for parts)
so about $40,000 for initial set op of a 24' diameter aquarium. and about $1000 a month in upkeep including food (but not water treatments like calcium and
ph buffers).