Large Diameter Acrylic Tubes

[spazz]

<a href=showthread.php?s=&postid=6730580#post6730580 target=_blank>Originally posted</a> by TANGBOY5000
Square skimmers work too.

not as well as round skimmers do. the corners can cause the bubbles to burst. even big ugly being octogon shaped is having a few bubbles break and combine in the corners. ask energy about it. he observed it happening. it wasent alot but its still a loss in performance. a square skimmer would react even worse than that.

 

[areze]

but if your talking about a square on that scale, the edges become exponentially tiny in the whole volume of the skimmer. youd have oodles of bubbles and still those same 4 small corners.



better questionis, how do you cut a 20" thick tube lol. I suppose a lathe or something... gotta be tough.

 

[ChemE]

What about putting a nice healthy fillet of caulking in the corners to help ease the sharp change in direction?

At the big cross sectional areas, square is way cheaper than circular. It sure would be nice to have our cake and eat it too.

 

[spazz]

I hear you. but if you look at any skimmer that is factory made. there all round. this is for a reason. more efficient design. square would be cheaper to build the body. if you look at big ugly. that body is 14.5" across and the corners are rounded corners. yet it still makes the bubbles pop and combine. this wouldn't be a problem if the air to water ratio was a lot lower than 12.5% any higher than 13% and the bubbles get huge. that's because there combining before they leave the pump housing. if you look at any of the big 3's skimmers. there is no sharp edges or square corners where the bubbles contact the acrylic. that's to prevent the bubbles form combining and loosing there grip on the proteins. think of the proteins as a fuzzy little ball. and the little bit of fuzz that's on the out side has to stick to the air bubble. that's not much surface area to have any grip on. then you hit a square corner and change direction abruptly. the bond will be lost. now you have 4 corners in that skimmer body. and the water is swirling around in the body. that will give that 1 protein multiple times to come in contact with 1 of 4 square corners. if you figure that 1 air bubble is in the body of the skimmer spinning around for 120 seconds, how many time will it come in contact with 1 of 4 corners in that body.
im not saying you shouldn't make a square skimmer. im saying it will be less efficient than a round body skimmer would be.