external overflow - need some input

IPT · #1 08/19/2007, 02:11 AM

I am going to drill a 50 breeder. My sump (size undecided) will be returned to the display with an Eheim 1260 to a Wavy Sea. My plan is to drill a single hole (1 3/4") in the upper left (or right). I'll encase that internally with a box about 10" long, maybe 5-6" tall and 1-2" front to back. No bulhead here just the large diameter hole left and covered with guttter gaurd or something like that to keep unwanted guests out of the external box. Trying to keep it unobstructive in the tank. The 1 3/4 hole will drain into an external box siloconed to the rear wall approx 10" long, by 8-10"s tall and 3-4" front to back. There will be two 1" bulkheads in the bottom of that. I like the drain method (herbie?) where one will function at full capacity as a siphon (ball valve if needed) and the second as a back up slightly taller than the first. Anyone see any problems here or have input or suggestions?? I'm all ears...

IPT · #2 08/19/2007, 01:57 PM

No one? I can't believe I am being a pioneer... I've seen lot's of external overflows on RC. Someone must be willing to share their experience.

wintercool97 · #3 08/19/2007, 03:49 PM

That seems like a good idea to me. Although being so new to overflows myself, my opinion isn't worth much. I don't know how much flow a 1 3/4" hole can handle, or that just one hole is an good idea. What if it some how got restricted? Maybe an backup hole there is a good idea as well? Just like the back up stand pipe? Good luck!

pito · #4 08/19/2007, 09:22 PM

Your way would work, but why have an internal box, and an external. You could cut weirs in the glass and eliminate the internal box. Or you couls eliminate the external box by doing it the calfo way. Personally, I'd loose the internal box. You could click my red house to see the weirs I cut on my tank.

IPT · #5 08/19/2007, 09:50 PM

pito - going with an internal box and no pipe in it so it can be thin (front to back). The weir, I don't want to cut the trim and take a chance grinding in a slot. Nervous enough about doing the one hole with a hole saw (the first is the hardest I hear). Calfo way requires some bulk in the tanl to get the fitting in right? I want the in the tank paet to be real thin so it doesn't stick out much. Still need some length to get good surface skimming though.

pito · #6 08/21/2007, 06:37 AM

Your way will work fine. Just be sure to verify that the hole sizes and box sizes will be able to handle your flow.

IPT · #7 08/22/2007, 01:27 AM

according to the calculator here at 600 GPH I need a 1" hole and 9" of linear run on the Overflow. The hole to the external will be almost double the size needed, and the overflow will be about an extra 3" in length. It's a 50 breeder and the return will be Eheim 1260 which is rated at 632GPH with no head. That shloud give me plenty of breathing room even if I wanted to Upgrade. Now I just need to find the Glass for the boxes and the Cajones to drill!

wintercool97 · #8 08/22/2007, 09:34 AM

Quote:

Originally posted by IPT
according to the calculator here at 600 GPH I need a 1" hole and 9" of linear run on the Overflow. The hole to the external will be almost double the size needed, and the overflow will be about an extra 3" in length. It's a 50 breeder and the return will be Eheim 1260 which is rated at 632GPH with no head. That shloud give me plenty of breathing room even if I wanted to Upgrade. Now I just need to find the Glass for the boxes and the Cajones to drill!

I used my dh Cajones to drill my tank!

But really it was easy to do. Just use lots of water. If you have a cement area to do it on that would be best. We only have an dirt yard at our new home and no side walks yet. Boy it was like mud wrestling!

barbra · #9 08/22/2007, 09:48 AM

You can do it! I recently cut a 2 foot slot in the back of my tank and I'm just a dumb girl

I would avoid any kind of a siphon setup though. They can't be counted on to do much more than drain your tank at the fastest rate possible.

argetni44 · #10 08/22/2007, 10:24 AM

generally a hole 1-1 1/4" will bring you anywhere from 800-1000 gph flow... just in case you were wondering

IPT · #11 08/22/2007, 03:35 PM

Well - cut my fiest hole last night. Just on a scrap, but it went well. A lot of skating around of the bit at first (becasue it was a scrap piece not clamped down. I had to hold it still eaving only one and a half hands to steady the drill). With two free hands to steady the drill I think it'll go fine when I do the tank.

Barbra - the idea of the siphon is to drain at max capacity so no air gets sucked it. It'll be silent. The ball valve slows the flow enough to match or closely match the flow rate. There is a second overflow as a back up should it get blocked or flowrates change. I'll max out the siphon and have just a trickle down the other drain. If that other drain gets real noisy from a lot of flow I'll now something is amiss. There was thread on here about the method a while ago.