Silent and Failsafe Overflow System

[Dudester]

BeanAnimal - First, a disclaimer. I have not read the entire thread. That being said, I've read quite a bit and I feel comfortable with the principles outlined regarding this overflow design. My previous tank used CJ standpipes, and years ago when I designed my (still dry) 450g tank I planned on using them again. But I like this idea VERY much since not only will this afford a silent overflow and eliminate salt creep, but it will also eliminate the need for a 'bubble tower' in the sump. I apologize if the answer to my question is contained elsewhere in this thread but I plan on using this design for my tank and I would appreciate your advice.

The internal dimensions of my external overflow are 31" long x 5 1/4" deep x 11 1/2" tall. The bottom of the overflow contains 4 bulkheads: two 2" and two 1.5". My initial intent was to use the two 2" bulkheads as drains into the sump, and the 1.5" would serve as potential return flow from peripheral tanks (e.g. frag tank, DSB, etc.) or some other system expansion. Instead, I'll now use both 2" and one of the 1.5" sites for this overflow system. I'll be using a Reeflo Dart pump as my return, which at around 5' head height will deliver approximately 3,000 gph back to the tank and, therefore, through the overflow.

I was considering using a 2" bulkhead as the primary (siphon) drain, a 1.5" bulkhead as the secondary (low flow) drain, and the final 2" bulkhead as the emergency drain. Does this sound wise or would you assign them differently?

 

[PJtree23]

BeanAnimal - First, a disclaimer. I have not read the entire thread. That being said, I've read quite a bit and I feel comfortable with the principles outlined regarding this overflow design. My previous tank used CJ standpipes, and years ago when I designed my (still dry) 450g tank I planned on using them again. But I like this idea VERY much since not only will this afford a silent overflow and eliminate salt creep, but it will also eliminate the need for a 'bubble tower' in the sump. I apologize if the answer to my question is contained elsewhere in this thread but I plan on using this design for my tank and I would appreciate your advice.

The internal dimensions of my external overflow are 31" long x 5 1/4" deep x 11 1/2" tall. The bottom of the overflow contains 4 bulkheads: two 2" and two 1.5". My initial intent was to use the two 2" bulkheads as drains into the sump, and the 1.5" would serve as potential return flow from peripheral tanks (e.g. frag tank, DSB, etc.) or some other system expansion. Instead, I'll now use both 2" and one of the 1.5" sites for this overflow system. I'll be using a Reeflo Dart pump as my return, which at around 5' head height will deliver approximately 3,000 gph back to the tank and, therefore, through the overflow.

I was considering using a 2" bulkhead as the primary (siphon) drain, a 1.5" bulkhead as the secondary (low flow) drain, and the final 2" bulkhead as the emergency drain. Does this sound wise or would you assign them differently?

Not sure but the emergency drain of 2" may not handle the flow. Also, it may be a difficult system to "tune" with the different sized piping. Otherwise it sounds solid

 

[TheFishMan65]

Not sure but the emergency drain of 2" may not handle the flow.

Why do you say this? As long as the emergency can go into siphon mode it should be able so support the flow.

Also, it may be a difficult system to "tune" with the different sized piping. Otherwise it sounds solid

Why would it be difficult.
You probably want to use a 2 inch as your low flow drain. 1.5 is probably big enough, but it has been mentioned several times that a larger low flow drain allows for a quite flow. Something about more wall area means a thinner sheet of water, and the larger air column allows less turbulence IIRC.

 

[PJtree23]

Why do you say this? As long as the emergency can go into siphon mode it should be able so support the flow.

Personally, I would build the fail safe drain with a higher safety margin due to junk build up over time causing restrictions.

I'll try and get a picture up of one of mine, but only after a few months I was surprised at the thickness of the gunk build up on the inner walls of the pipe. Plus snails or what ever.

Why would it be difficult.
You probably want to use a 2 inch as your low flow drain. 1.5 is probably big enough, but it has been mentioned several times that a larger low flow drain allows for a quite flow. Something about more wall area means a thinner sheet of water, and the larger air column allows less turbulence IIRC.

To completely silence the system and ensure that the full siphon of the main drain engages after a power outage the pressure at the ends of the pipe have to be "tuned" or adjusted (relative to one another) in order to minimize noise and "start-up" time. If the pipes are a different diameter it may be more difficult to find the correct setup.

I had to adjust the length of pipe which was under the water in my sump such that full siphon engages first, thus it is not as deep in the water. The partial siphon has a longer extension into the sump placing the outlet deeper in water creating more outlet pressure.

The emergency drain length does not matter as I don't have mine siphoning rather just a tube with an inlet open at the top of the pipe versus U shaped with a Durso.

IMHO

 

[TheFishMan65]

Gunk in an emergency (fail safe) drain? It should be dry? Are you sure you don't mean the low flow or open channel?

The siphon drain should only be about an inch below the water level. I have heard of people having trouble getting the siphon to start, but don't recall any evidence that the pipe size makes a difference. I wouldn't think it would matter, but perhaps someone more knowledgable (you ?) could explain why/if pipe size affect tuning/start up.

 

[Dudester]

Interesting discussion guys, and thanks for addressing my question. Actually, after thinking about it further, it may be smarter for me to use a 1.5" as the primary siphon drain, and use the 2" drains as the secondary (low flow) and emergency drains. I have read accounts of using a Barracuda as the return pump with 1.5" drains, and that functioned fine. My Dart will have less flow than a Barracuda, so the 1.5" pipe should be able to handle the high flow portion, while taking advantage of the increased surface area of a 2" drain for the low flow. Does this seem like a better option?

 

[TheFishMan65]

That is what I would have done.

 

[Names Brucey]

I have run both a Hammerhead and a Dart now as my return pumps with 1.5" piping with zero issues. The 1.5" keeps up just fine. I agree with Fishman that I would use the 1.5 as your main return. It will be easier to adjust in my opinion as the other two are really set and forget (they all are once it is dialed in).

 

[slow_leak]

This a nice set up to run with potential for overkill at lower flow rates.

Most questions have been discussed, but I can not determine why main siphon overflow has a sanitary T with a capped vertical standpipe.

Wouldn't an elbow be sufficient if it is true siphon? Anyway I'm sure the answer is buried in the last 146 pages...

 

[RocketSurgeon]

This a nice set up to run with potential for overkill at lower flow rates.

Most questions have been discussed, but I can not determine why main siphon overflow has a sanitary T with a capped vertical standpipe.

Wouldn't an elbow be sufficient if it is true siphon? Anyway I'm sure the answer is buried in the last 146 pages...

It allows for simple routine maintenance.

 

[slow_leak]

It allows for simple routine maintenance.

Ah yes the pipe cleaner brushes. Thanks!

 

[SpacedCowboy]

@the fish man - I think what you suggest seems reasonable. I think I'll give it a go when I get back from Europe ... Just lying in bed at 4:50 cursing jet lag ATM

Simon

 

[cfsindorf]

What ever happened to Bean?

 

[TheFishMan65]

A lot of folks are real busy on here for a while and then lag off. I figure it is their real job, person issues or vacation. I am sure he will be back.

 

[BeanAnimal]

What ever happened to Bean?

It is the 29th of July at 9:30 and this is page 146, Post #3635

My last post in this thread was on the 23rd of July at 9:30 PM on page 145, post #3614

So I was active in this thread less than 6 days and 21 posts ago.... I average over 6 posts per day...

In any case, I also visit other areas of RC as well as this thread. I try to let other folks jump in and help here. I only answer when I have time to provide thoughtful answers or see that others are unable to provide reasonable or proper answers.

There have been numerous questions asked in the last 7 days and I have not had a chance to read all of them, let alone answer them. That said, it does appear that other members of the community have stepped in an provided reasonable answers.

 

[BeanAnimal]

Hey Mr beananimal,
th the issue as I see water just collecting below and stagnating ?

Any advice and help would be very much appreciated.

First of all... try note to post so many large photos on one page, while most of us have broadband, it still takes a while to load

You can use the standpipes as drawn. stagnation will not be a problem. If it is, you can fill the box with sand to create a small DSB. In a shallow box, the intakes are set close to the bottom of the box to prevent snails from getting sucked on. In a taller box this is not a problem.

If you set the pipes LOW in the box, then you are going to have a noisy waterfall, defeating the purpose.

 

[3xion]

Thanks for taking the time to reply mate,

Looking forward to getting it setup, and working was just a little daunting to start with, everything seams to be coming along alright now, again thanks for replying hard to get a decent answer on plumbing from other forums.

[Tried to keep the pics under 300K each (don't know if I succeeded but agreed)]

Thanks again

Regards,
3x

 

[BeanAnimal]

Hey Bean

Any thoughts on what I or TheFishMan65 mention above ? No great hurry because I'm just about to leave for Europe for a couple of weeks, but I *am* curious

Cheers
Simon.

Trying to tie them together with a pipe is not worth the effort. Using an "open channel" in each box may work, but if the flow through those open channels is that low to begin withm then are you really getting that much more surface skimming? 90% of the flow is through the siphon and therefore the box with the siphon will do 90% + 5% (open channel) if the surface skimming anyway.

If the siphon does 80% of the flow and the rest is split between the two open channels, then you still only get 10% of the flow going through the other open channel, still marginal (at best) gains.

 

[TheFishMan65]

Can you please tell me why tying them together is not worth the effort. I haven't tried it (I think I said that), so I must be missing something in my understanding of plumbing.

Thanks

 

[BeanAnimal]

The internal dimensions of my external overflow are 31" long x 5 1/4" deep x 11 1/2" tall. The bottom of the overflow contains 4 bulkheads: two 2" and two 1.5". My initial intent was to use the two 2" bulkheads as drains into the sump, and the 1.5" would serve as potential return flow from peripheral tanks (e.g. frag tank, DSB, etc.) or some other system expansion. Instead, I'll now use both 2" and one of the 1.5" sites for this overflow system. I'll be using a Reeflo Dart pump as my return, which at around 5' head height will deliver approximately 3,000 gph back to the tank and, therefore, through the overflow.

I was considering using a 2" bulkhead as the primary (siphon) drain, a 1.5" bulkhead as the secondary (low flow) drain, and the final 2" bulkhead as the emergency drain. Does this sound wise or would you assign them differently?

Use the 1.5" as the primary siphon, and the 2" as the open channel. Your choice as to what to use for the emergency. The 1.5" siphon and 2" open channel will laugh at the Dart