Poriferan's 350

[Poriferan]

I have found a "sweet spot" for the overflow that makes it virtually silent. Only problem is the water touches the cross brace a little when the waves are in that area.

I am still torn on removing the teeth to allow greater flow and lower the water line a bit.

Does removing every other tooth seem like a compromise? I am no engineer but my logic dictates that if I reduce the restriction from the weir by increasing the surface area across it, more water should flow and/or lower the height of the water behind the weir on the tank side...

Anyone?

This is a video before I hit the quiet "sweet spot".
Overflow vid

 

[dave.m]

Judging from your photos and video I would have to say the teeth are not the problem. The height of the water in the overflow is almost the same, inside and out. Your stand pipe is too small to handle the amount of flow you are feeding it. Are you restricting the flow in any way? If so, open it up more, else you'll have to reduce the amount of water you are sending from your return pump. What happens if you remove the cap on the stand pipe?

Dave.M

 

[worm5406]

Inside the overflow I have 1.5" drains. One is running full siphon and had to be slowed down to stop the air from entering

Why is that?

I agree with dave.m the water height is too high in the overflow. Bring it up to speed a bit more. How was it making air enter?

(it is currently (beananimal style?)

That requires a full siphon, a wet line, and a dry emergency. (three pipes)

 

[woodnaquanut]

To add to worm's BA comment, when you have one siphon and one emergency you have a Herbbie not BA.

From the video (way too short and not enough light back there to see what is really happening!), it does look like you have more flow than the weir can handle. Teeth really cut down on flow and make it much more turbulent. Effective length of the weir is total length minus teeth.

I'm guessing your siphon has to be cut back so it doesn't drain down and suck air. Is that right? The siphon can handle more flow than the weir.

You have some options.
1. Cut down return flow so the tank doesn't overflow. Adjust the siphon to just keep up with this flow. Traditional Herbbie has a dry emergency.

2. Remove some/all of the weir teeth. This will greatly increase the effective size of the weir and allow much more flow. Now you can up the return flow. Then adjust the siphon so it just handles the flow, keeping the emergency dry.

In either case I'd have the top of the siphon (think upside down 'U') about 0.5-1inch below the top of the weir and the emergency about 0.5 inches above the top of the tank water level.

All shown on this great sketch :eek2:

 

[woodnaquanut]

I turn down the flow from the return pump a little and am running at the maximum the teeth can handle. The water rushing through the teeth makes a lot of noise. I can slow the exit of water through the full siphon to raise the level in the overflow (this reduces the noise) but that causes water to flow through the emergency drain. I am thinking I may have to change the emergency to a straight siphon so I can raise it above the water level (it is currently (beananimal style?) similar to this with an added airline at the top and no pipe extending down to the bottom of the overflow.
View attachment 305008

My other thought is to dremel off all the teeth. I think that would allow for around 50% more flow into the overflow box, lower the tank water level around 1/2 an inch, and give more leeway for emergency pipe height selection. Problem is the tank is running and this would have to be done by lowering the water level a bit inside the tank.:headwalls:

I see no reason for the siphon to reach all the way down to the bottom of the OF box as in the pic.

Cutting the teeth is a big commitment to altering your new tank. Proceed with caution. Is the weir acrylic? I'd practice on some to see how easy cutting is. Tap Plastics often has scraps for just a few $$.

Slow return flow to some level the teeth can handle w/o making noise. Lower the siphon and don't make the emergency a siphon. If this results in flow lower than you desire the only recourse is to cut them teeth out. Time for a dentist.

 

[cFloor]

Lookin good! I really like the aquascape

 

[Poriferan]

To add to worm's BA comment, when you have one siphon and one emergency you have a Herbbie not BA.
Thank You for clarification. I wont sound uneducated now

From the video (way too short and not enough light back there to see what is really happening!), it does look like you have more flow than the weir can handle. Teeth really cut down on flow and make it much more turbulent. Effective length of the weir is total length minus teeth.

I'm guessing your siphon has to be cut back so it doesn't drain down and suck air. Is that right? Yes, it will suck air if I open it any more. The siphon can handle more flow than the weir.

You have some options.
1. Cut down return flow so the tank doesn't overflow. Adjust the siphon to just keep up with this flow. Traditional Herbbie has a dry emergency.

2. Remove some/all of the weir teeth. This will greatly increase the effective size of the weir and allow much more flow. Now you can up the return flow. Then adjust the siphon so it just handles the flow, keeping the emergency dry.

In either case I'd have the top of the siphon (think upside down 'U') about 0.5-1inch below the top of the weir and the emergency about 0.5 inches above the top of the tank water level.

All shown on this great sketch :eek2:

Thanks for all the advice.

The tank level causes the water to touch the braces at the currently operating flow. If i open the drain a bit more, the level drops but the full siphon sucks air.

The weir is acrylic so removing teeth would not be too difficult with the proper dremmel router bit.

I adjusted and tested the emergency overflow but the sump runs out of water before the emergency goes into full siphon. I will need to test it again with more water in the sump. Problem is that the ATO would be adding water to compensate if the main siphon stopped working. I don't think it would be enough to make too much difference in 400 gallons total volume though.

 

[woodnaquanut]

The tank level causes the water to touch the braces at the currently operating flow. If i open the drain a bit more, the level drops but the full siphon sucks air.

Is the open end of the siphon close to the top? Assuming it's a few inches below the weir teeth, you just need to keep adjusting till it hits it's 'sweet spot'.

It's a balance thing and it doesn't seem like you've hit balance yet.

Also, if the siphon is too high you might try lowering it a bit. You want the water flowing into the OF to drop a small amount after the weir teeth.

Are you MARS member? You might want to reach out to the club members for an onsite visit.

 

[Poriferan]

Lookin good! I really like the aquascape

Thanks! It seems to be easier to figure out with more room.

 

[Poriferan]

This is a little better picture of the weir.



This is where everything lived when the 225 sprung a leak. I lost about half my fish and 75% of the corals (excluding the sofites)

 

[Poriferan]

A few from today.









I really need to improve my tank picture taking skills. The LED's really give me a hard time:wildone:

 

[worm5406]

This is a little better picture of the weir.

Where is the full siphon and emergency in that picture?

To me something does not look right.

 

[Poriferan]

Full siphon is under water. Emergency is the herbie style standpipe on the right. I turned the 90 up to keep it just above the waterline.

 

[dave.m]

What is the path of the full siphon pipe? There should be at least one and preferably two 90° bends to even out the flow and control air/bubbles in the effluent.

Dave.M

 

[Adam G]

So your main is under water and not restricted at all? That means it is taking all the water it can as fast as it can. A couple of ideas: A siphon drain acts like a siphon so lowering the sump will give it more head room and water will flow faster. Not sure if you can put your sump lower or even move down the pipe where it flows into your sump to give it even 6 more inches of drop should help.

 

[worm5406]

Will your sump support all the water? Can you add more SW to compensate?

One is running full siphon and had to be slowed down to stop the air from entering.

In a test, what happens if you crank the full siphon to 75% open and raise the water flow?

 

[Poriferan]

Full siphon has two electrical long sweep 90's. It can handle a lot more flow as I have to restrict it to get the level in the overflow to be high enough to stop pulling air into the siphon.

I am convinced that I either have to go with less flow or cut off the teeth. I have the pump slowed right now and am guessing I get around 2000 gph through the sump. The current total water volume is a little less than 400 gallons.

 

[Poriferan]

Will your sump support all the water? Can you add more SW to compensate?



In a test, what happens if you crank the full siphon to 75% open and raise the water flow?

If I raise the water flow the level in the tank rises. I cannot run a full speed as the tank would overflow (even with both siphons full open, that was my first test.)

 

[woodnaquanut]

If I raise the water flow the level in the tank rises. I cannot run a full speed as the tank would overflow (even with both siphons full open, that was my first test.)

So raising return flow...
Does the tank overflow because water can't get into the OF box fast enough or the drains can't keep up?

Using the return flow from the latest pic:

Is the submerged siphon (unseen) valve fully open?

If it's not, and you open it some does the siphon drain fast enough to pull air?

What does the top of the siphon look like? Is it just an open stand pipe or is it topped with 1 or 2 elbows?

The drain (emergency?) I can see looks a lot more like a Durso drain. I thought typical Herbie e-drain was just a stand pipe.

Some good pics of a Herbie:
http://gmacreef.com/herbie-overflow-reef-tank-plumbing-method-basics/

His pics, drawings and animation is just a little bit better than my sketch! :lol2:

 

[Poriferan]

So raising return flow...
Does the tank overflow because water can't get into the OF box fast enough or the drains can't keep up? Water level in tank rises too high, water cannot get into the overflow fast enough.

Using the return flow from the latest pic:

Is the submerged siphon (unseen) valve fully open? No, it is closed several turns on the gate valve.

If it's not, and you open it some does the siphon drain fast enough to pull air? Yes, if I open it 1/32th of a turn (a tiny bit) the level in the tank and overflow drop. This causes the waterfall noise in the overflow as the water rushing in is now dropping and splashing. Another tiny turn and it will begin to pull air.

What does the top of the siphon look like? Is it just an open stand pipe or is it topped with 1 or 2 elbows? Top of siphon has a strainer but is otherwise pointed straight up.

The drain (emergency?) I can see looks a lot more like a Durso drain. I thought typical Herbie e-drain was just a stand pipe. I think you are correct. I did not know the names of the different styles. It is a T capped above the waterline. The top of the cap as a (John Guest) airline looped back to be under the waterline if it raises too high. Other branch of T has a 90 that is currently turned up.

Some good pics of a Herbie:
http://gmacreef.com/herbie-overflow-reef-tank-plumbing-method-basics/

His pics, drawings and animation is just a little bit better than my sketch! :lol2: