New to scrubber

[SantaMonica]

Is going to work well.

[Floyd R Turbo]

Hey when you get it fired up let me know. I want to do a beananimal overflow on my new 120 w/scrubber and have been posting to see if anyone else has tried it. SM uses a Herbie and says it works fine. I was worried that the full siphon standpipe wouldn't purge fully. I was thinking that I would use a larger than suggested open standpipe (maybe 1.75" instead of 1.5") to allow the siphon to run full but allow for slowdown towards the end of the week before cleaning. However that may not be necessary but I don't know, not many have been providing me feedback (or didn't look at my posts). I won't be starting my build for at least 4 months so I've got time to plan it out and work all the kinks out. Let me know how well yours works please!!

[Fishuntbike]

I've been using this overflow (without ATS) for 2 years now and I don't see any difference in flow with the ATS installed. I got so much flow going on there even just using 1" pipe and it is quiet for my 40 breeder. I recommend to go atleast 1.25 pipe to 1.5 to make it much quieter but bigger that that is not neccessary. I have 3 overflows and 2 of the overflows are kept dry (as failsafe) so that i can get the most from the main overflow at full siphon. To tell you how is the flow right now, I don't even have my main overflow valve to fully open (15% less) due to water is being drained so quickly from my weir.I have to grind to lower lower the lip of my weir so that water fill the weir quickly to compensate the main overflow drain speed. You'll have no problem with this set-up. Hope this help
I will take pictures to show you how mine is

[Floyd R Turbo]

Awesome.

As for having to grind your weir down, why would you have to do that? Lowering the weir wouldn't increase the flow rate over the weir, it would just lower the top of tank water level. The flow rate over the weir is dictated by your return pump. If you want to get more flow so that you can open your siphon standpipe valve fully, you would need to increase your return pump flow rate by getting a bigger pump or increasing your return piping diameter. For instance, if you're running a Danner Mag pump, you need 1.5" minimum return pipe (regardless of pump nozzle output size)

It sounds like you have it working almost right. You're supposed to have it the way you're running it from what I understand, you partially close the full siphon valve so that it's operating at full siphon and you get laminar flow down the open channel standpipe. You have it tuned right to the edge of operation, with no flow down the open channel. I think this is not recommended because if there's any change in water level - lets say you stick your arm in the tank, then take it out, causing a momentary drop in tank level - then you would break the siphon. You should close your siphon standpipe valve a bit so that it's operating at less than full capacity and you get water running down the open channel but not enough to cause it to gurgle

Or am I missing something that you were describing?

[SantaMonica]

A tuned full-siphon is somewhat self-adjusting. If you put your arm in, the water level goes up, increasing presure on the siphon, and thus the siphon will flow more. If you put two arms in, it will probably start going down the emergency.

[Fishuntbike]

the lip of my overflow box is totally flat, giving it a little angle in the mid-section will make the water to rush in to the weir without dropping my tank level. When this overflow is tuned properly just like SM said it is somewhat self adjusting and putting hand to the tank will raise your water level and siphon will not break but instead it will flow more. I use 3 street elbow, the one turned down is full siphon while the 2 that are up are emergency. For the full siphon I shorten the elbow to accomodate higher water in the box.

[Floyd R Turbo]

I think both of you missed what I was getting at.

lets say you stick your arm in the tank, then take it out, causing a momentary drop in tank level - then you would break the siphon

Yes I understand that putting your arm in the tank will cause more water to get displaced over the weir. My point is that if your full siphon is running at 100% and the open channel standpipe at 0% (no flow in it) then if you pull your arm out of the tank, the flow could momentarily stop over the weir and your siphon could potentially break. Not like it's the end of the world, your siphon would just have to re-start. But this is why you do not want your full siphon standpipe running at 100%.

The point of the 3-pipe "silent" system is to have the full siphon pipe running at less than 100% of the total flow, and have the open standpipe taking up the slack, enough so that the water is coating the inside of the pipe but not so much that it causes coverage across the entire cross section anywhere in the pipe (which would cause the gurgle).

If you grind down your weir, like you described, this would not change the situation, it would only raise the level of water in your sump and lower the level of water in your DT, assuming that the volume of water did not change before and after. You will have exactly the same amount of water falling over the weir because the rate of flow over the weir is dictated by the flow of the return pump. It will just flow a little more over the angled mid-section, which will concentrate your surface skimming to that area, effectively decreasing the effectiveness of the weir because of the decreased effective width.

I follow your logic, but I think you're looking at it the wrong way. So don't take all this the wrong way, I'm not trying to get on your case or anything like that, I'm just trying to save you some time!!

I'm glad you put up that picture though, because it helps me understand the situation. What do you mean by "For the full siphon I shorten the elbow to accommodate higher water in the box."?

Also, it doesn't look like you have an open-channel standpipe in your design, you have 2 emergencies. Which is fine, but you might lose the intended functionality of the open-channel standpipe. Having 2 emergencies will probably do the job about the same. But if you turn one of the up-turned elbows slightly sideways, and then close your siphon ball valve a teeny bit, you will have some water flowing down 1 emergency pipe, and the full siphon should hold in the event that you put your arms in the tank and then remove them.

[Fishuntbike]

I see what you are saying about momentary loss siphon when removing from the tank but it is so quick though to flood the box and return siphon and that is not my concern.In regards to the 3 street elbow with 1 turned down and 2 are emergency, I did that because I use the main full siphon for the ATS so that I have all the water flowing to the ATS instead of going to the other pipe. Without the ATS I have that set-up which beananimal design is utilized, but with the ATS my concern is to get all the flow I can get from it. I mentioned that I cut the the street elbow (which is the one turned down) by doing that the water in the box went a little higher allowing me to open the valve a bit. Regarding the grinding of the lip of the box I am still debating if that will help, and I follow what you said and you are probably right on that. I have another bigger pump that I'll try this weekend, will see. Goodluck to your coming build

[Floyd R Turbo]

I get what you are getting at w/r to getting the full siphon going 100% to the ATS. It's one of my concerns with the BA system. The way you solve it is to drill the hole for the open standpipe about 1/4" higher than the full siphon standpipe. I've seen that suggested several times to solve people's issues with getting the FS started quicker.

When you say that you cut the street elbow, do you mean that you shaved off the part of the elbow that extends downward toward the bottom of the box so that it does not come as close to the bottom of the box? How did that allow the water level in the box to raise?

[Fishuntbike]

I believed the 1/4 hole beibg suggested is to allow air to come out so that the water will flow on the pipe wall and get 100 % full siphon. Anyways the cut elbow is exactly you said to be not close to the bottom of box, it let the water in box to go up till hit the lip of the elbow and start siphon. I also tried having 3 elbows facing up with different heights making the shortest to full siphon the next short one give a flow to the next pipe and the 3rd as dry. All the testings make a little changed but not much. I think changing bigger pump will suffice every need to ATS