I decided I need more tanks but I wanted to run them all off one big canister filter. In my little mind I had it all worked out and everything was going to be great. In reality my knowledge of physics obviously isn't as good as it once was, or fluid dynamics is just a whole different animal.

My thought was to simply make U shaped pipes, fill them with water, then invert them with one side in each tank. I figure it works in a sump set up it should work from tank to tank. The reduction in water on one side of the pipe would create a draw and it would pull water from the tank next to it. This happened but even with 3 seperate 1" pipes all going from the same two tanks the water level was higher on the return side. When I added a third tank the return was the highest, the middle was 1/2" lower, and the intake was 1/2" lower than the middle.

I first did it with just 1 pipe from each tank, then went to 2 then 3 but the levels are exactly the same. I checked each of the pipes and could feel suction so they are all passing water. One other note is the U is more of an r since one side is longer than the other.

Anyone know what I'm doing wrong?

Another question the tanks have stickers on the bottom that say "tempered glass" does that mean it's all tempered or just the bottom? I think drilling them would be much easier but I don't feel like shattering a side glass on one to find out.

OK I figure a couple pics would do better than my description:


THis shows the current configuration with 4 tanks the intake is the far left tank, the return is far right.



Here is the overhead view, I went back to 2 pipes per tank because it didn't effect the water height at all with 3 pipes.

The canister is a Fluval FX5 that I governed down using the shut off valves. If it runs at full open it would overflow the first tank in about 20 seconds.

FishVixen wrote:What about increasing the diameter size from 1" to 1.5"on the return side 1" in center and .75" on intake using the same design.

That was what I tried doing by adding the extra pipes. Did 3 at the return tank, 2 in the middle and 2 at the intake, still looked the same. The part I don't understand is the 2 tanks to the left are almost the same level. I think I'll add tank number 5 to see what happens.

I already know I have to just switch to overflows and a sump but figured since these are tempered tanks I would try it before going to buy nontempered that I can drill. I just ordered 50 bulkheads so I guess I have a new DIY for the contest.

If I don't sell the 240 soon I think it will become the sump.