Silent and Failsafe Overflow System

Swope2bc said:
Am I mistaken that Bean used 1" bulkheads for cost with 1.5" pipe? I believe he stated flow rates consistently at or beyond 2000 gph. That being said, the reason I would go with all 1" would be for cost, and because I already have 1" hole saws. Now, if 1" would not be sufficient I could upsize.

Keeping in mind that my return pump maxes out at 1500gph but is a dc pump and will run about 50% essentially. Also, this is only a 40b. Do I truly need to go bigger or will 1" meet my intended use without trouble?
Click to expand...

I wasn't saying that a 1" bulkhead wouldn't work, at your flow levels, it would work fine. I was saying that there is no downside to using 1.5" bulkheads. For that amount of flow, ideally I would run my siphon with 1" lines, and for the open and emergency run 1.5" lines. If you already have the hole saw for the 1" bulkheads, then I would use that. If was starting from scratch and didn't have any bulkheads or holesaws, I would probably run the larger bulkheads in case you want to upgrade to a larger return in the future, or if something went down your emergency, it would stand a better chance of making it all the way down without getting caught at the bottle neck where the smaller bulkhead is. However, it is a minor point, and probably not worth the money you would spend buying a different hole saw and more bulkheads.
 
thejuggernaut said:
I wasn't saying that a 1" bulkhead wouldn't work, at your flow levels, it would work fine. I was saying that there is no downside to using 1.5" bulkheads. For that amount of flow, ideally I would run my siphon with 1" lines, and for the open and emergency run 1.5" lines. If you already have the hole saw for the 1" bulkheads, then I would use that. If was starting from scratch and didn't have any bulkheads or holesaws, I would probably run the larger bulkheads in case you want to upgrade to a larger return in the future, or if something when down your emergency, it would stand a better chance of making it all the way down without getting caught at the bottle neck where the smaller bulkhead is. However, it is a minor point, and probably not worth the money you would spend buying a different hole saw and more bulkheads.
Click to expand...


Thanks Juggernaut, no sought larger for those would be better. But, as you have well said, the advantage may not outweigh the extra cost. Thanks for all the help!
 
thejuggernaut said:
I wasn't saying that a 1" bulkhead wouldn't work, at your flow levels, it would work fine. I was saying that there is no downside to using 1.5" bulkheads. For that amount of flow, ideally I would run my siphon with 1" lines, and for the open and emergency run 1.5" lines. If you already have the hole saw for the 1" bulkheads, then I would use that. If was starting from scratch and didn't have any bulkheads or holesaws, I would probably run the larger bulkheads in case you want to upgrade to a larger return in the future, or if something went down your emergency, it would stand a better chance of making it all the way down without getting caught at the bottle neck where the smaller bulkhead is. However, it is a minor point, and probably not worth the money you would spend buying a different hole saw and more bulkheads.
Click to expand...

Actually, for lower flow systems, some people have reported problems with the larger bulkheads, presumably because the lower flow velocity prevents the line from purging the air.

Bigger holes are not always benign either, but assuming they are properly spaced and drilled, that shouldn't be an issue.
 
I could see where that could be an issue with a horizontally drilled bulkhead where the bulkhead is actually the high point. I don't know if it is such a concern with vertically mounted bulkheads. From my personal experience, I have run a 1.5" bulkhead necked down to 1" PVC on both sides. On startup it would purge with all the air removed from the line in less than 15 seconds after applying power to the pump. That was at about 600-700 GPH. I never ran it lower than that. Running all 1.5" PVC and bulkheads, I could get it to purge with a mag 12, but it would take about 45 seconds. So I felt uncomfortable with that, cause I felt it was right on the verge of being too slow to purge. But just by scaling up the PVC lines to 1.5" across all three drains, I could run 3000 GPH and could completely clog any two lines and the 3rd would handle it fine. I posted a video showing everything I just described, with the system running at different flows and simulating different clogs several pages back. You can see how quick it purges even with a small 600-700 GPH. There are so many variations on this design now, that it is impossible to give hard and fast rules. Like Uncle says. He guarantees it will work if you build it just the way he does. Deviate in any way and it's as-is no-warranty. LOL
 
Yeah - if it's going straight down it would probably be fine. A lot of people put an inverted U over the siphon standpipe, so I'm not sure how it work in that case.

Of course, since you can run over 2000 gph with a 1" bulkhead and 1.25/1.5" pipes, there are very few people who need a larger bulkhead anyway.
 
I'd appreciate any comments/thoughts on my plumbing plans.

I have a 120g Corner-Flow Marineland tank. As some of you might know, it is drilled for 1" bulkheads. There are two holes, so I am going with a Herbie. The PVC provided for inside the tank is, if I recall correctly, 1.25". My notes aren't in front of me...

Anyway, I plan to use a bushing to go from the 1" bulkhead to 1.25" (just under the tank) for both the siphon drain and the emergency drain. From reading the above, it seems like I should just stick with the 1". Thoughts? I did buy a few feet of 1.25" flex PVC for this purpose, but that's not much money within the total cost of the build...

What size PVC should I use above the bulkhead?

Other than that, I plan to follow the instructions on the gmacreef website. Actually, it was suggested to me that I terminate the emergency drain about an inch or two over the water, so that I can hear the noise to let me know there is an issue.

I've seen conflicting comments about how much the Corner-Flow can drain, in that I've read some people say that the weir can't handle over 700 gph and some say that the durso which comes with the tank can't handle over 700 gph. I'll be using a Fluval SP4 pump, with a manifold to run two reactors (and room for more).

Thanks for any thoughts/comments.
 
How far down in the overflow do you drill the holes for the three pipes? I have a 24" CPR overflow on a custom 50 gal I'm building. Can I space the three pipes evenly across the 24"? I bought all the parts that was listed at the beginning of this monster thread... Lol. So its all 1.5 with 1" bulkheads but now I'm wondering if I should scale it down to all 1" pipe. Sump is a large magnavore about 3 feet below tank. Thanks.
 
pavehawk said:
How far down in the overflow do you drill the holes for the three pipes? I have a 24" CPR overflow on a custom 50 gal I'm building. Can I space the three pipes evenly across the 24"? I bought all the parts that was listed at the beginning of this monster thread... Lol. So its all 1.5 with 1" bulkheads but now I'm wondering if I should scale it down to all 1" pipe. Sump is a large magnavore about 3 feet below tank. Thanks.
Click to expand...

This thread talks about guidelines for hole clearances. In general, minimum 1 diameter between edges, 1.5 preferred.

For horizontal spacing it doesn't matter too much; I would position them were it works for your sump to make the plumbing easy.

As far as vertical spacing goes, you can read through this thread to see my thought/design process. The vertical position depends on the box, your water height, the elbows, desired clearances, etc.

They don't make a 24" CPR overflow box; did you mean the 18" RSS24? Were you planning on doing internal/external or strictly internal?
 
Thanks. I will check out those threads as the vertical is what is stopping me from putting drill to tank. Yes I have the 18" it will be internal. Do you think the 1.5 plumbing will be fine with my 50 gallon? I plan on using the new reef octopus DC pump.
 
What kind of flows and what size elbows were you planning on using? looking at the box, it's only 4" wide, so you don't have a ton of room.

1.5" plumbing will be more than adequate for you. You could easily downsize to 1.25", even 1" for the siphon channel. I would I would use a 1" gate valve on the siphon regardless, just because the 1.5" valves are a lot more expensive. You do create a theoretical bottleneck where something could get stuck if you do this, but assuming you have 1" bulkheads, anything that gets through the bulkhead should get through the valve as well. (the bottleneck won't be an issue for flow, so don't worry about that)

I left about 3/4" of space between the bottom of my overflow box and the bottom of the elbows. You may want to leave more with your box. The toothed design means it will tend to be noisier, especially with a large drop, so having the water level a bit higher in the box will help to minimize that.
 
I bought 1.25 street elbows. I think I will go with the gate you recommend, I already bought 1.5 ball valves but they are a pain to turn. thinking around 500 for flow its a 50 gallon tank. I will double check the space I have in the overflow.
 
I am planning out a internal c2c with external box for my 40b build. All glass will be 1/4".

I'm wondering what the optimal distance between the tank trim and the top of the overflow would be. (I was leaning toward 1/4").

As of now I was thinking of making the c2c 3" tall and 1 3/8" deep. Should I make it bigger?

I'd like to add a sheet of 1/8" black cast acrylic to the vertical part to hide plumbing. I would keep the top of the acrylic 1/8" from the top of the weir. Same for the part of the external that is attached to the tank.

Im going to drill 2 or 3 1" holes for the water to travel from the c2c to the external box. I was thinking 3 would be better since it spans 12". Any insight is appreciated.

Could I position these holes so they're just above the bottom horizontal glass of the c2c? At this point a drop would be about 2" to the bottom of the external box.

External box will be 12" long 5.75" tall. I'm going to build my stand extra deep so the plumbing can travel straight
Into the sump with no elbows (except for the street at the intake). There will be around a 52" head. According to the calculator on beans site a siphon would drain around 2500gph 1" from 52" head and a 3/4 at around 1400gph. I don't need what the 1" is capable of and have read that 3/4 open channel and emergency is pretty useless for noise reduction/safety.

Could I have a 3/4" siphon and 1" open channel/emergency?

I'm not concerned with having complete silence, my main concern is safety in the event of a drain being clogged.

Lastly. Does just the siphon empty 1" underwater or should I have all three? If I'm correct the siphon won't let out air bubbles but an open channel will if it's under water. Assuming the same for emergency because at that point I don't care about bubbles the clog would be more of a concern.

Apologize for so many questions but I've read this thread front to back and it's a lot to absorb.

Any advice is much appreciated, thanks for taking the time to respond to this thread!

-Mike
 
pavehawk said:
I bought 1.25 street elbows. I think I will go with the gate you recommend, I already bought 1.5 ball valves but they are a pain to turn. thinking around 500 for flow its a 50 gallon tank. I will double check the space I have in the overflow.
Click to expand...

Bean used ball valves in his original design, but gate valves are much easier to fine tune and what virtually everyone uses for their siphon channel. The other valves bean used on the emergency and open channel drains are unnecessary
 
SpikeDangles said:
I am planning out a internal c2c with external box for my 40b build. All glass will be 1/4".

I'm wondering what the optimal distance between the tank trim and the top of the overflow would be. (I was leaning toward 1/4").

As of now I was thinking of making the c2c 3" tall and 1 3/8" deep. Should I make it bigger?

I'd like to add a sheet of 1/8" black cast acrylic to the vertical part to hide plumbing. I would keep the top of the acrylic 1/8" from the top of the weir. Same for the part of the external that is attached to the tank.

Im going to drill 2 or 3 1" holes for the water to travel from the c2c to the external box. I was thinking 3 would be better since it spans 12". Any insight is appreciated.

Could I position these holes so they're just above the bottom horizontal glass of the c2c? At this point a drop would be about 2" to the bottom of the external box.

External box will be 12" long 5.75" tall. I'm going to build my stand extra deep so the plumbing can travel straight
Into the sump with no elbows (except for the street at the intake). There will be around a 52" head. According to the calculator on beans site a siphon would drain around 2500gph 1" from 52" head and a 3/4 at around 1400gph. I don't need what the 1" is capable of and have read that 3/4 open channel and emergency is pretty useless for noise reduction/safety.

Could I have a 3/4" siphon and 1" open channel/emergency?

I'm not concerned with having complete silence, my main concern is safety in the event of a drain being clogged.

Lastly. Does just the siphon empty 1" underwater or should I have all three? If I'm correct the siphon won't let out air bubbles but an open channel will if it's under water. Assuming the same for emergency because at that point I don't care about bubbles the clog would be more of a concern.

Apologize for so many questions but I've read this thread front to back and it's a lot to absorb.

Any advice is much appreciated, thanks for taking the time to respond to this thread!

-Mike
Click to expand...

The top of the overflow determines the water level in the tank. Depending on your flow, it the water level will likely be 1/8~1/4" higher, but should never be appreciably higher. I would just put the glass at the bottom of the tank trim (where the trim is on the outside glass, not the inner rim.)

The height of the CTC doesn't matter much, assuming it clears any bulkheads you may have. You will have a hard time getting a piece of glass cut 1 3/8" x 36", you may want to consider using 2 pieces of glass for the bottom or using a single piece of glass and angling it.

You are correct that a 3/4" open channel is pretty useless. You can have a 3/4" siphon and 1" open channel. The only problem with a 3/4" siphon is that it's harder to clean and very easy for critters to clog.

Have all 3 empty under water. The open channel will be carrying water all the time and if you don't have it under water the splashing will cause a lot of noise, salt creep and potentially dampness that can cause other problems.

The holes between the overflow and your external box should ideally be centered on the water level. I'd shoot for about a 1" drop to avoid excess splashing for the reasons mentioned above. You also need to be at least 1 hole diameter from the closest adjacent glass edge when drilling your holes.

what will your external box be made out of and how are you attaching it? If it's glass, you need to make it wide enough to safely drill the holes as I just mentioned. If it's acrylic, you need to have some means of securing it to the back of the tank(silicone will not work)
 
Thanks for the quick reply. So the bottom Part of the L on the c2c is 1.75" and I'm going to have the vertical 3" piece on top of it leaving 1 1/5" not 1 3/8". I am a commercial glazier so getting pieces of glass like this aren't difficult as they are usually drops (free).

I'm going to make the external box out of 1/4 glass as well and I purchased RTV 103 to attach both the internal and external part of the overflow.

So the 1" bulk head I'm using requires a 48mm diamond hole saw to be used. That equates to a little less than 2". Should I make the box deeper so that I can have 2" from all other holes and edges? With the box being 5 3/4" currently it's only 1 3/8 from the edge.
Considering the cost of the glass I should probably just do it. Let me know what you'd reccomend.

Thanks again
 
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