I saw the video link someone else posted here on this and I finally made it. I use a 3/4 gallon tank suspended in a 35 gallon long and the open end is about an inch into the bigger tank. I just ran the venturi air line from my powerhead up to the top inside of the smaller USD tank and it sucked all the air out! Now I have my fish swimming from one tank into the other at will and it's pretty cool. I didn't think a venturi had the suction to do this but I was wrong! I'll post pics when I can get my GF's camera back.

Sweet, these are so cool. I can't wait for pictures!

Now that I see how easy it is I plan to put a 5-10 gallon upside down on my new 35 gallon long planted. I want a nice cube of some sort and I'll put a SHO compact florescent screw in light w reflector so I can grow taller plants up into the USD tank. What I have now is only 3/4 gallon and It's all taped up with sticks keeping it from falling down. I'll make this nicer with some thick wire slings and borrow my GF's camera for pics. The minnows look pretty cool up in there and it kind of looks like a habitrail or something for fish. Definitely an easy way to increase the size of a tank vertically.

It's just a little 3/4 gallon tank and I could just reach up to clean it when I need to. There's plenty of snails up there now, so they're doing some cleaning. This couldn't be more simple to make. By far the hardest part was suspending the USD tank. the rest was just to put an extension on the venturi air line and sticking it up inside. That's all there is to it. Actually unless you're letting bubbling air into this tank you don't even need to have the powerhead. Just use your lungs and suck the air out via an air tube. It'll stay full of water.

It would look best with a really clean looking cube. The only problem with the one I have now is that I had to push the light all the way to the back of the tank, which works with a 3/4 gallon USD tank OK, but if the USD tank were wider it would be a problem. I could put a screw-in CF with reflector over the cube nicely, but I would need to get a 2 foot long light for the plants in the lower part. I'd like to get one of these heavy wood tree stumps and have the broken trunk part go up inside the USD tank and have anubias and Java fern growing on it. Have a stream of bubbles going up into it as well and have a powerhead constantly sucking the air out the top kind of like the you-tube one we looked at a month or so ago.

I will I will. She likes a little spanking. I'm expecting her to start begging to move in with me with her kids and I'm keeping my foot down on that. I lived with her once and I did all the work! I bought all the food, cooked all the meals, paid all the bills, and she undermined all my effective parenting. It was a nightmare and I hated having my son in that environment. Her kids would probably pour soap into my aquariums if given a chance. She's living with her mom, sister with kid, and her 2 kids in a 1 bedroom apt, and she's getting an inspection from the courts about custody with her ex husband soon. She doesn't make enough money, has bad credit, and she's gona lose her kids if she doesn't get it together and live in a better place with those kids. I learned my lesson though and she aint movin with me!!! I have to put a plug in my truck's tire because I ran over a bolt. Then I'm going to the hardware store to get some tomato plants and some metal rod so I can make a nicer suspension system than what I was using for the USD tank. I took it down so I could have the light work for my plants, but I'll set it up again in another tank and then take pics.