Not too hard to fill either submerge in one tank then a plastic bag over each end and lift into place. Or set in place and use a wet and dry shop vac to suck out the air through a length of hose.
Well my answer would be to run a air hose up and suck it out by mouth then pull out the hose.
My question is how do you clean one of those out? I had a design in mind but I can't figure how to clean one, or make one that can easily dissassemble and be cleaned??
Yeah, cleaning would be be a major chore. Imagine algae growing through the whole length. If it was more than for a side by side tank, you'd probably have to make it so that you could disassemble it somehow, or have an army of BN Plecos working for you.
I was thinking about this idea I origanlly wanted to have a large hexagon 200 gallon plus tank and my old 75 gallion fish tank and maybe a 500 to a 1200 main master fish tank and then have all the fish tanks in diffrent rooms of the house such as the hexagon tank would go in the dinning room or my bed room and the 1200 gallon master tank would go in the living room while old 75 gallon tank would go in the dinning room. They would all be linked up by six inch across clear pvc pipe which goes for 200 dollars for a ten foot section of it. I would also give eatch fish tank a different theam such as one would be all large rocks and gravel another would be all plants and even one would look like a coral reef.
There was a website I remember selling that sells clear pvc pipe in up to 14 inch across sections.
As for this idea change well when I joined this site I now want to have two cement fish tanks one on reach end of the house and a six to ten inch across clear pvc pipe that would run from one end of the house to the other for the fish to swim though.