Silent and Failsafe Overflow System

[clownfish06]

I have a 75 gallon tank I am going to drill it to work with this setup and wanted to know if I just need to get the 1 inch diamond drill bit and drill holes 3 inches from top of tank to make this work. Tank is not rimless by the way. I have been reading the thread all morning and am glad I found it because you have solved all my worries about the overflow box with this idea.

 

[chrisfowler99]

Ok...a bunch of reading and I've (so far) pared it down to a single question:

How deep (front to back, not top to bottom) does the overflow box need to be?

I ask this because most drawings/pictures I see make it appear that the elbows that are in the bulkheads couldn't have been inserted after the box was built and there's no way they (along with the bulkheads) could be removed and replaced. I'm assuming that they are solvent welded to the bulkheads which would mean that, in order to have them removable in the future the overflow would have to be deep enough to pull the elbow and the bulkhead out together.

And...as I type this...I realize that the whole system is welded, so, in order to remove any piece it would all have to be cut, seriously reducing the necessary room to remove/replace parts. Which means, I'm guessing, that the overflow needs to be just deep enough to be able to install the bulkhead and to weld the elbow to the bulkhead, which would make it necessary depth of the overflow slightly larger (by the bulkhead's "head") than the total depth of the elbow.

Am I making any sense?

 

[teesquare]

uh....nope

If you re-read the thread - you will find that there are several methods that have been tried - and some of them work very well!:beer:

But - I am not sure you grasp enough of it quite yet, and I am not trying to be mean-spirited by saying that - just go back tot he very first four or five pages of this thread. It will really help you get a much better feel for the system.Virtually all of your questions will be answered in those pages.

Note - I do not glue any fittings INSIDE the overflow. I use silicone.....( But - you will see that if you read up from this post a page or two - but some feel they need to glue and - that works for them.)

Best o' luck!

T

 

[coralcruze]

Hey bean...
I wonder if you may be able to help me with a slight issue I am finding with my system. You may recall I have that waterfall tank that i custom built no too long ago? anyway, everything was working great however, when I allow more flow to be pumped into the tank (by opening a ball valve on the supply line) and then shut the system down to simulate a power outage the full siphon line does not kick in as the water rises past it and the secondary failsafe always turnes into a full siphon first. what can I do to prevent this from happening? currently I need to block the secondary to get the full siphon to start on the primary line. what should I do? should I cut down the primary a bit more to create more head preassure? Its already 1" lower than the secondary... Please advise. thanks

 

[BeanAnimal]

The siphon standpipe is not purging the air fast enough. How far below normal operating level in the sump does it terminate? You can also drill a few small holes in the siphon standpipe, just above the water line (normal operating level) in the sump.

 

[jesserettele]

Hey Bean, this has been an awesome thread thanks!

Here is what I have so far. What do you think? What would you change or do different?

I used 1 1/2" 90 degree elbows to keep everything low profile because I am not going to use a canopy and want to flush cover the external overflow. I know that I also need to add the durso style vent in the 2ndary drain as well. The 1 1/2" PVC is a slip fit into the abs bulk heads and I am not planning on cementing them so that I can remove them to clean them (I thought this would work instead of the removable top caps in your sanitary "T's" design. The problem I see is that the non cemented slip fittings won't be water tight enough???

I would appreciate any feedback and/or comments.

 

[uncleof6]

Hey Bean, this has been an awesome thread thanks!

Here is what I have so far. What do you think? What would you change or do different?

I used 1 1/2" 90 degree elbows to keep everything low profile because I am not going to use a canopy and want to flush cover the external overflow. I know that I also need to add the durso style vent in the 2ndary drain as well. The 1 1/2" PVC is a slip fit into the abs bulk heads and I am not planning on cementing them so that I can remove them to clean them (I thought this would work instead of the removable top caps in your sanitary "T's" design. The problem I see is that the non cemented slip fittings won't be water tight enough???

I would appreciate any feedback and/or comments.

That tank was a rimmed tank, and the glass looks a bit thin to be a rimless. I would seriously consider euro bracing the tank for safety. Off topic, but necessary. Also those radii, for the notch, need to be smoothed and cleaned up. Looks like chipping, and these are likely crack points.

Jim

 

[jesserettele]

Thanks Jim, I filled it with water after I removed the rim (which didn't have a center brace to begin with and has 3/8" thick glass) and there was only 1mm of bowing, should I still consider euro bracing? If so the only avenue I found was water jet cutting to get a single solid top piece like this

This would cost about the same as a brand new rimless from glasscages.com from the quote that I got.




The edges are a little rough but the corners were drilled with a 1/2" hole saw before the cuts were made.

I am thinking of applying glasscages.com trim over the overflow to cover it up and reinforce it. Would this be sufficient?

 

[TheFishMan65]

"The problem I see is that the non cemented slip fittings won't be water tight enough??? "
If you glue the two 90 elbos together I thing you should be OK. The connection to the bulkhead should alays have a good amount of water over it. So you can take out the upper plumping from the bulkhead (it would be one piece for each bulkhead) for cleaning.

 

[uncleof6]

Thanks Jim, I filled it with water after I removed the rim (which didn't have a center brace to begin with and has 3/8" thick glass) and there was only 1mm of bowing, should I still consider euro bracing? If so the only avenue I found was water jet cutting to get a single solid top piece like this

This would cost about the same as a brand new rimless from glasscages.com from the quote that I got.




The edges are a little rough but the corners were drilled with a 1/2" hole saw before the cuts were made.

I am thinking of applying glasscages.com trim over the overflow to cover it up and reinforce it. Would this be sufficient?

The overflow itself, should not be a problem as it is, but a rim for it will hurt nothing. The back panel, should not be an issue either, except for the chipping. (The overflow acts as support-- depending on the grade of silicone you used. If a consumer grade was used, I would be concerned about the overflow staying in place.

The tank should be euro'd front to back at then ends, and along the front panel. No need to go so elaborate with the water jet cutout. 1mm may seem like not much, but the seams are not going to like it over time.

Jim

 

[jesserettele]

Fishman, that's exactly what I was planning on doing. Do you think the radius of the 90 degrees is too small?

Jim thanks again, PM sent in order to stay on topic here in Bean's thread.

 

[TheFishMan65]

IIRC a 1.5 siphon drain is going to handle the flow of most pumps. The tighter bend will limit that some, but unless you are talking a couple thousand gallons an hour. You should be fine.

I just check bean site 1.5 at 12 inches of head will flow 2600+ gallons an hour.

 

[coralcruze]

The siphon standpipe is not purging the air fast enough. How far below normal operating level in the sump does it terminate? You can also drill a few small holes in the siphon standpipe, just above the water line (normal operating level) in the sump.

thats exactly right the siphon doesn't purge the air from the pipe fast enough to start the full siphon...

In my situation the drain pipes enter the sump through the side walls of the sump via a bulkhead and the pipes terminate about 2.5" from the operating level. drilling holes in the pipe is not an option unless I plumb in back into the sump somehow...

Just tonight I checked and apparently the left sides full siphon line was cut about 1/8" lower than the right I'm going to try this. what about doing a 1/4" loop line on the main siphon line as you have on the secondary line. do you think this will help with establishing a full siphon quicker? any ideas what else I can try?

 

[BeanAnimal]

The 2.5" is what is kelling you. You have very little head height to begin with and the force of the falling water is not enough to overcome the air lock in the standpipe.

Yes, you can try adding a loop line to the siphon standpipe to allow it to free flow slightly before the siphon kicks in. This may or may not work depending on how fast the overflow box fills and covers the intake of the air loop. It will have to be fairly low to keep the system from sucking air during normal operation.

 

[coralcruze]

The 2.5" is what is kelling you. You have very little head height to begin with and the force of the falling water is not enough to overcome the air lock in the standpipe.

Yes, you can try adding a loop line to the siphon standpipe to allow it to free flow slightly before the siphon kicks in. This may or may not work depending on how fast the overflow box fills and covers the intake of the air loop. It will have to be fairly low to keep the system from sucking air during normal operation.

I was afraid you'd say that... I could cut the baffel in my sump down an inch which would lower that operating water level in the sump compartment that recieves the full siphon line. theoretically I could cut it down more than an inch but i would hate to loose the water voilume in there. What is the recomended water level that the siphon line needs to be submerged into the water in the sump? Remember in my case its a side wall entry so when I ask the above in my mind I'm thinking the very top edge of the pipe to the top of the water line.

 

[poppafish29]

Does it matter from left to right in the overflow where the holes are drilled for the stand pipes (left/center/right)??? In Beans original design, he has them all on the left side of the over flow.

 

[TheFishMan65]

No it does not matter.

 

[poppafish29]

Thanks FishMan.
What about the height of the holes??? I noticed that most people keep all three holes at the same height, but others drill the open channel a bit higher.

 

[TheFishMan65]

Open channel a little higher give the siphon more time to start - there have been a few posts with this problem. I think it is a good idea, but it is not required.

 

[poppafish29]

How much higher is everyone drilling the open channel? 1/4" OK?