connecting 3 tanks at the same height

The scenario;
3 tanks on stands all in a row that are the same height.
From left to right:
1. 55 gallon reeftank well established
2. 75 gallon reeftank well established
3. 75 gallons empty

My empty 75 gallon was originally bought to become a sump. I'd rather have it stay on the stand and be something worth viewing yet still perform task to help water quality in the other 2 tanks. Maybe a huge refuge with some interesting critters. Maybe a section at the end with a big proteing skimmer sticking out of the top.
One idea is to use aquarium water bridges to connect the 3 tanks. This way all tanks would be level and no flood would occur if there was a siphon failure. I would like to incorporate a pump to increase the flow between tanks but that may also increase my risk of a flood.
I thought that first I would get the 2 reeftanks connected after getting their parameters close- then add the 3rd. Perhaps the water bridge would be a good way to slowly acclimate each tank to the others.

Does anyone have useful comments?