overflow boxes needed?

[bdr]

getting ready to start my plumbing and im working with a 90g drilled tank. do you need an overflow box as ive seen in so many pics? why couldnt you just bring the pipe above the water and cut grooves into it down to the height of where you want the water?wouldnt that achieve the same thing and leave alot more room in the tank?

[dublo8]

Yes, it's the same idea but an overflow is larger, thus creating more turnover, granted it's moving the same amount of water, the overflow "box" has more surface area than a single piece of pipe.

[Andrew17030]

What happens when you crack the bulkhead or need to make a change to the overflow pipe for some reason? All it takes is a slip off balance working under the tank into the drain pipe to put too much stress on that bulkhead. Then you have a situation! The idea of an over flow is to be able to take all of the plumbing out and not have to drain the tank to do it. Things happen in this hobby that are very unexpected sometimes. People that have had tanks for any amount of time will all tell you this is true. Now whether you NEED an overflow is not what I am saying. You certainly have thought about it and have found that you can achieve a constant water level in the display without an overflow. The other question is are you talking about drilling the tank at the water level through the back/side or through the bottom. You have thought it through this far so I assume that you can understand what I am saying. I love well plumbed tanks. I especially like when it can be done cleanly and with as little PVC as possible. Check out the clean plumbing thread, you will see a lot of nicely done plumbing. YOu can also search youtube and see professionals putting together bonds the right way. When i started I just hacksawed the pipe and threw glue on and I was done. I had a lot of leaks. Good luck and good plumbing!

[bdr]

My tank is drill in the top corners (tempered bottom) so even if the tank need to be drained to work on it the level will only need to drop 5 inchs so thats kind of a non issue. Im an electrician not a plumbler but we work with pvc all the time so i wont be showing any coworkers if it doesnt turn out good for my first try As for volume of water if it is the same 2 1.5" drain lines how would the box change the drain rate? I kind of assumed the box just kept the critters out from going down the drain? but the same depth and width teeth that came an inch or two above the water would do the same thing id assume but thats why im here asking is we all know what assuming does! thanks for the replies

[dublo8]

Yes, the box keeps the critters out as well and the teeth help to keep your water level...well....level. Some people also use coast to coast overflows, meaning it goes from one side to the other. You want as much of that surface water to be removed as fast as possible and an overflow box allows this. A single drain line without a box will remove the same amount of water but not all of it being surface water.

[funkejj]

Boxes are so cheap and easy to silicone on it is a moot point in my book.

[bdr]

Originally Posted by dublo8

Yes, the box keeps the critters out as well and the teeth help to keep your water level...well....level. Some people also use coast to coast overflows, meaning it goes from one side to the other. You want as much of that surface water to be removed as fast as possible and an overflow box allows this. A single drain line without a box will remove the same amount of water but not all of it being surface water.

ok that sorta makes sense when your talking more of a volume of surface water i can see how you would take a thinner slice over a greater area so both work both take the same water just the box spreads it out over an area