I HAVE AN IDEA!
YOU WOULD HAVE THE FAN OF THE WIND ATTCHED TO A PULLY SESYTEM AS IT WENT AROUND IT WOULD PULL A ROD UP & DOWN THE ROD WOULD BE CONNECTED TO AN AIR PUMP LIKE THIS AND THE PUMP WOULD BE FASTENED IN PLACE.
AND IT WOULD PUMP AIR INTO THE TAKE EVERYTIME IT CIRCLED YOUR OTHER IDEA IS GOOD TO BUT IT MIGHT MAKE THE TAKE ALITTLE NOISER FOR THE FISH WITH THE SLAPPING OF THE WATER. I LOOKED EVERYWHERE AND THAT WAS THE BEST I COULD COME UP WITH... I HOPE IT HELPS I READ YOUR WHOLE THREAD AND IT IS THE BEST THREAD I HAVE EVER READ I JUST READ ALL 17 PAGES AND I HAVE TO SAY THAT YOU WERE THE MOST UP TO DATE ON YOUR PROJECT MORE THAN ANYONE ELSE ON THE SITE. THANK YOU SO MUCH IT IS REALLY HELPFULL SORRY I COULDNT FIND A BETTER SOLUTION FOR YOU BUT I DO THINK A BUBBLE MAKING DIVICE WOULD CAUSE LESS DISTURBANCE TO THE TANK.
YOUR FISH ARE SO BEAUTIFUL THERE COLOR IS LIKE YOU SAY THE BEST I HAVE EVER SEEN.