have a 75 and a 30

i was thinking about making one wet/dry for both and have them next to eachother... i have a fluval 405 on the 75 and an aquaclear 110 on the 30 for now... is there anyway to make an overflow from the 75 into the 30 and have the intake from the fluval in one tank and the output in another? what are my options guys. the 75 has a gar in it and the 30 has some convicts and african ciclids