Calfo Style Overflow boxes
- Thread starter Jeremy Blaze
- Start date
fiveplusfive
New member
Running a closed loop through the overflow defeats the purpose of the external calfo design if the purpose is for more efficient skimming.
However if the purpose of the external overflow on a small skimmerless system w/sump were to make intake and return pipes less visible inside tank while maintaining a quiet system would the following example work?
Pipes left to right:
1 - Siphon to sump
2 - Open to sump
3 - Emergency to sump
4 - Closed Loop Intake
Two identical pumps (1 fuge & 1 CL) both sending return over back top of tank.
Is this reasoning sound?
(FYI all 4 pipes are durso, but my CAD skills are lacking)
However if the purpose of the external overflow on a small skimmerless system w/sump were to make intake and return pipes less visible inside tank while maintaining a quiet system would the following example work?
Pipes left to right:
1 - Siphon to sump
2 - Open to sump
3 - Emergency to sump
4 - Closed Loop Intake
Two identical pumps (1 fuge & 1 CL) both sending return over back top of tank.
Is this reasoning sound?
(FYI all 4 pipes are durso, but my CAD skills are lacking)
asnatlas
New member
How much room would I need for the "gap" on a Calfo Style Overflow ?? I am looking at a 48x36x25ish tank. I wanted to have the ext overflow box on the left side of the tank (36" side). I was going to have the builder just leave that pane X amount shorter. I was thinking like 1/4-1/2" but wanted to see what others had to say... The ext box is going to be around like 36x12x7wide
firebirdude
User and Abuser
This right here..... is HOT!:eek2: I am SOO doing that!<a href=showthread.php?s=&postid=10226361#post10226361 target=_blank>Originally posted</a> by flyyyguy
Im sure this has been done before......but here is my ghettofied version of a near coast to coast overflow "box" using nithing but 2 bulkheads and some PVC pipe. I set up a 46 gallon tank for a friend and came up with this. I use external coast to coast overflows on my tanks, but this was a super simple way to achieve near coast to coast surface skimming, it took less than a 1/2 hour to make and install and you cant even see it in the tank.
simply put.....2 bulkheads, 4 street elbows inside the tank and a piece of pipe with a groove cut out on the table saw 3 notches wide. The overflow is removable by simply lifting it out. The street L's are water tight this way. that part kind of surprised me as i figured over the course of a night it would drain down to the bulkheads...but they didnt.
pics...this of course doesnt go the entire length of the tank, more like 2/3...but it just as easily could have, and it skims the surface great. Its also no louder than the Snapper used to power the CLS.
firebirdude
User and Abuser
But question..... this setup would seem to be EXTREMELY dependent on water level. If evaporation takes the water down 1/2", it won't reach up into the slit. And likewise, if the tank is overfilled, you'll get plenty of water in, but you won't get the skimming effect.
BeanAnimal
Premium Member
<a href=showthread.php?s=&postid=13445979#post13445979 target=_blank>Originally posted</a> by firebirdude
But question..... this setup would seem to be EXTREMELY dependent on water level. If evaporation takes the water down 1/2", it won't reach up into the slit. And likewise, if the tank is overfilled, you'll get plenty of water in, but you won't get the skimming effect.
The level of the overflow dictates the water level in the tank. The return pump fills the tank until it overflows...
Jeremy Blaze
Former Reef Addict
I just want to say how proud I am this thread has gone so far!
firebirdude
User and Abuser
Duh. You're right guys. I'm an idiot.:hmm4:
So how could I ballpark flow on something like this? Strictly go off the linear length of the slit? But that would yield some very large numbers. For example, only 18 linear inches would achieve 1200gph! Trying to get a ballpark to match up a return pump.
So how could I ballpark flow on something like this? Strictly go off the linear length of the slit? But that would yield some very large numbers. For example, only 18 linear inches would achieve 1200gph! Trying to get a ballpark to match up a return pump.
thats the wrong way to think about it
you shouldnt run any more water through your overflow than your skimmer can process. so your skimmer IMO should dictate how much water you are putting through your overflow.
If you send way more water by your skimmer than it can process, then you are completely defeating the purpose of surface skimming in the first place, as you are intentionally just recircing the "dirty" unskimmed water right back to the tank
asnatlas
New member
What would be a recommended "gap" from the overflow ledge to the underside of the eurobracing ?? I would say for my current skimmer would be like 600ish GPH... I would like to not limit it to that as I do plan on upgrading to a diff skimmer... Maybe get another BK as I had before, but I don't think they are rated at a much higher feed rate ??
firebirdude
User and Abuser
The water will also run through a fuge. Just FYI.
And I was just looking for some ballpark figures. 18" @ 1200gph seemed a little high. Since I'm not looking for THAT much flow.... maybe I'll only make it 3" long. lol (kidding..... but to prove a point)
firebirdude
User and Abuser
What overflow box?!?! I thought the entire idea of this thread was to avoid the overflow box.
firebirdude
User and Abuser
Uh.... have you looked through this thread?
The overflow is just a piece of PVC pipe with a slit cut in it. Each end of the PVC pipe is then plumbed through a bulkhead and runs straight down to the sump. Despite the title of this thread, there is no box.
The overflow is just a piece of PVC pipe with a slit cut in it. Each end of the PVC pipe is then plumbed through a bulkhead and runs straight down to the sump. Despite the title of this thread, there is no box.
BeanAnimal
Premium Member
Uh.... have you looked through this thread? You may actually want to read a thread before trying so hard to make a fool of somebody, save you end up playing the fool.
A calfo overflow is NOT
It is an internal (or external) overflow box that runs the lenght of the tank. Also known as a "coast-to-coast" overflow.
firebirdude
User and Abuser
I certainly wasn't trying to make anybody into a fool, so can the lecture please. I did use the words "I thought." Perhaps both styles have been discussed in this thread?
From earlier in this topic:
From earlier in this topic:
