Help designing Calfo style box
 

I am in need of some advice before I drill. My tank is a 125 long (72"x18"x20") and I want to add a calfo style overflow that will span half the length of my tank. My plan is to drill and install 2 1" bulkheads to feed the skimmer portion of my sump. Water will be returned via a Quiet One 4000. What I am looking for is how to determine the dimensions for the box. Not the length of course but how tall and deep to make it. Also where is the best place to position the bulkhead i.e. high or low in the box. My main concern is noise. Any input would be appreciated.

Thanks

i think the typical size would be about 4-5" wide and about 6-8" deep..height of the bulkhead will dictate how much drop yo have in the box...less drop = less noise...

that said i would likely put the BH at a level where there would be no more then 1.5" of drop from the top of the weir to the water level inside the Calfo...provided your pieps are sized to the flow of the QO4000 then the water level in the overflow should be pretty much at the top of the BH...therefor the top of the bulkheads should be about 1.5 inches below the top of your your weir...you may want to drill a third bulkhead and cut one side of the elbow off to about a 1/4" or 1/2" and upturn it as a very noisy backup drain to indicate there is a problem should one of your drains become plugged...

I have a 36" 50 gallon and I made my box 18x4x4. If I had to do it over again I would keep the length the same, it gives me 26 inches of overflow including the sides.

The width is the min I would go since I wanted to have screen on the bulkheads in case a snail or fish got and they have. it is enough width to allow me to unscrew the 3" screens for cleaning. The problem, even with just 4" width and clear bottom is that it blocks some light. There is a shaded spot under the overflow which is not horrible, but I can see it. Since my tank is only 15 inches wide a 4" overhand for the overflow is significant.

The 4" depth is not enough. Without a screen the 1" bulkheads would suck in air and it would make noise. I tried down turned elbows but that will start a siphon and controlling water level in the sump became very hard and I just really didn't want a siphon. I tried a tee with a hole in the top, but it would still suck in some air. With screen the slurping sound is less, but it is still there. It will make a little noise every 10 seconds or so as some air gets sucked down. If the overflow were an inch deeper along with the bulkheads I think it would be fine.

i have a 120g with a calfoesque overflow. i made the overflow box 4"x4". i made it just big enough to fit an upside down elbow in the box with about 3/8" space between the elbow and the bottom of the overflow box. this keeps the gurgling down and prevents anything larger than 3/8" of an inch from getting into the drains(snails mostly). hope that helps

check out my little red house you'll see some pictures.

Do you have any problems with flow with that little of a box? I am thinking about this for a new tank I don't have yet. How many and what size bulkheads did you install?

take a look at my build thread (little red house). It's only 4" high and 4"deep but it's 3 feet long in a 4 foot tank so it can handle more than enough flow. I also went with 4-1" drains because i'm a big fan of overkill. i'm sure i could've gotten away with 2.

shyland83 thanks for the tip on your build thread. It answered questions I did not know I had. Honestly, I think I am trying to be too meticulous on my first reef. I am just worried about the hang on overflow I bought failing. I am now having second thoughts about the company I picked to do the drilling. It got weird when the owner said "If I poke dem holes in yer tank water is gonna fall out. Taint dem suppost to hold water in em?" Yeah, I am in Texas.

Have the guy practice on a 3/8" thick pane of glass before drilling your tank if you're worried. I did a calfo overflow on my 120g I used two seperate overflows...one for the refugium section..the other for the sump. I use 1.5" CPVC T's simply snug fitted into the threaded bulkheads. The suction holds them there and snails don't bother it. I've placed small pieces of gutter-guard in the T's to screen stupid fish or inverts. The reason for the description is that if allowed I would shorten my boxes to 3 - 3 1/4" out from the back of the tank as the T's don't require any "outward" clearance to set in place. My box is the standard 4x4" out. I eliminate all noise by placing the T's on their side and by incorporating an durso-style aspirating tube into the plumbing as it drops below the display, feeding the sump and refugium. The only other neat thing is that I also used greyed or smoked glass and sch80 PVC to make the unit visually obscure.

I would go with (3) 1" bulkheads.

The box should be sized deep enough to hold down turned street elbows and wide enough to remove them if needed.

With (3) bulkheads you can achieve a dead silent setup with NO AIR being introduced to the sump.

The first standpipe will run at full siphon and be regulated by a ball valve set to NOT quiet handle the full flow of the return pump.

The second standpipe will have a fully open valve and an air inlet in the top (like a durso). This standpipe will handle that little bit of flow tha that the first standpipe is set to reject.

The third standpipe will have an upturned (or partially upturned) elbow with strainer. This will act as an emergency standpipe if the water level rises too high. It will also may kick in on startup before the main standpipe starts to siphon.

The setup is very failsafe, never needs adjustment and is dead silent. It is very self tuning.

Re: Help designing Calfo style box
 

[QUOTE][i]<a href=showthread.php?s=&postid=11558433#post11558433 target=_blank>Originally posted</a> by zojro [/i]
[B]I am in need of some advice before I drill. My tank is a 125 long (72"x18"x20") and I want to add a calfo style overflow that will span half the length of my tank.....Any input would be appreciated.
Thanks [/B][/QUOTE]
This is on a 58G tank. One inch bulkheads. Scale it to your dimensions.

[IMG]http://www.reefugium.com/pix/overflow1.jpg[/IMG]

[IMG]http://www.reefugium.com/pix/overflow2.jpg[/IMG]

[IMG]http://www.reefugium.com/pix/overflow3.jpg[/IMG]

[IMG]http://www.reefugium.com/pix/overflow4.jpg[/IMG]

[IMG]http://www.reefugium.com/pix/overflow5.jpg[/IMG]

[IMG]http://www.reefugium.com/pix/overflow6.jpg[/IMG]

[IMG]http://www.reefugium.com/pix/overflow7.jpg[/IMG]

Re: Re: Help designing Calfo style box
 

[QUOTE][i]
[IMG]http://www.reefugium.com/pix/overflow6.jpg[/IMG]

[/B][/QUOTE]
What kind of hose couplings are these? Sorry to hijack but this is the nicest overflow and return I think I have ever seen.

Re: Re: Re: Help designing Calfo style box
 

[QUOTE][i]<a href=showthread.php?s=&postid=11565083#post11565083 target=_blank>Originally posted</a> by swamprat [/i]
[B]What kind of hose couplings are these? Sorry to hijack but this is the nicest overflow and return I think I have ever seen. [/B][/QUOTE]
[url=http://www.banjocorp.com/]Banjo[/URL] locking cam lever couplings.