Yes indeed, you do spy a concrete slab floor rumpus:D that rumpus is bigger than a double garage, AND the ceiling is into the house so will retain heat well:D
IF i end up buying it, i will turn the downstairs int o a 'henward den'
2x lazy boys
huge tank/s
locust breeding again
mealworm farm
lazy boy is from parents old suite, so might as well lol
dont have a problem treating rain water, recalling, i cant drill a hole on the concrete wall lol so cant have auto changer, so will be a semi auto change.
i will still do the sump drain thing, but will attach to a large bore hose and take it to the storm rain by the rumpus and pump fresh new water into the tank and drain like i am doing now,
maybe invest in a stronger pump to quickly pump water through from drum to tank, no biggie.
I figure, 3000 to 3600litre system total, the stocking is less than half of my 1200litre, i thin i can get away with a small wc a week! nitrate concentrations will be low due to the volume and low stockig. Dont mind a semi manual change 1x a week, 2x even for when i decide to go nuts with feeding and growint out:D