Durso drain noise reduction

[Haberdasher]

Sounds like a good plan. Good luck!

 

[Heavymman]

Can you provide a pic of what's happening in the sump on the drain side? Are you getting bubbles from drain in the sump?

@Haberdasher I forgot I took this video before draining. I might just add a gate valve to the overflow and not drill any holes in the tank.

 

[Matthew Frost]

Couple quick questions, can you turn the pump down a little bit? Is your drain outlet below the surface in the sump?

 

[Heavymman]

Couple quick questions, can you turn the pump down a little bit? Is your drain outlet below the surface in the sump?

Yes, it’s a COR 20 and I had it down to 10% and played with it for a whole day to see if I could tweak it , unsuccessful. And yes drain outlet was below waterline, I’ll add a pic.... I think it was the turbulence of the water coming into the sump that maybe a valve can fix. I don’t know enough though.

 

[Matthew Frost]

After watching the video I have some more questions/thoughts. Your Durso appears to be at capacity or very close. Can you walk me through the plumbing, the drain - every fitting and the rough pipe/tube lengths from the tee at the top to the last piece of pipe at the bottom. What size is your bulkhead in the tank? Why did you go with a COR 20?

 

[Heavymman]

After watching the video I have some more questions/thoughts. Your Durso appears to be at capacity or very close. Can you walk me through the plumbing, the drain - every fitting and the rough pipe/tube lengths from the tee at the top to the last piece of pipe at the bottom. What size is your bulkhead in the tank? Why did you go with a COR 20?

I went with a COR 20 because I got a good deal on it and I have an Apex system. I have a 1” drain bulkhead and 3/4” return. I am using schedule 80 behind the acrylic overflow and I have a threaded bulkhead, to slip and then I have the tee, with a street elbow facing down. I have an end cap with 1/4” whole and tubing on (played with a 1/4” valve to see if I can get it right). Everything underneath the stand is tubing.

 

[Matthew Frost]

Judging by the water line on the weir teeth you're turning over a lot of water, more than you probably need to. I think your barbed fittings are really choking your drain line. Can you get a hard fitting 1 1/2" to thread onto the outside of that drain bulkhead? My suggestion would be to scrap the flex drain rigid plumb the drain with at least 1 1/4" rigid pipe. Come straight down off the bulk head and add a valve. Turn a 90 right off the valve and add a union. Take the pipe through another 90 and turn it down straight over your filter sock. Run the drain all the way down under the water line. That should quiet the whole thing down a lot.

PS you don't need Schedule 80 fittings anywhere on a tank this size, your just spending extra money.

 

[Matthew Frost]

Here's how I put mine together, its 1 1/2" hard line. I have the union and valve reversed because of space and access.

 

[Heavymman]

Here's how I put mine together, its 1 1/2" hard line. I have the union and valve reversed because of space and access.

My holes in the tank will only permit me for 1” and 3/4” plumbing. I thought flex doesn’t have as much restriction as hard plumbing?

 

[Matthew Frost]

Its the barbed fittings, they create a real choke point. Your COR 20 is moving a lot of water and a 1" drain is struggling to keep up because its gravity fed. You want to try and open that drain capacity up as much as you can.

 

[Heavymman]

Its the barbed fittings, they create a real choke point. Your COR 20 is moving a lot of water and a 1" drain is struggling to keep up because its gravity fed. You want to try and open that drain capacity up as much as you can.

But if I took that 1/4” tubing out of the air hole, water mine dropped... also I reduced the return pump to a minimum and still had an issue.

 

[JumboShrimp]

Just an option / food for thought: If you want to build a way to return water to the far end of your tank, then BOTH of your drilled holes could be used as drain holes, instead of just one. You could likely increase your overall flow in the process.

 

[Matthew Frost]

The best way I can describe it is you want the drain line to be able to move significantly more water than your return for several reasons. If anything gets in It and blocks up the system it still drains. The other often overlooked reason is velocity. A bigger drain pipe the water doesn't have to move as fast and is therefore quieter. If we can slow the water down in a larger pipe or a combination of pipes it will be quieter.

 

[Matthew Frost]

The reason your drain is so loud is partly because of volume but more because of the waters velocity when it gets to the sump.

 

[Matthew Frost]

Just an option / food for thought: If you want to build a way to return water to the far end of your tank, then BOTH of your drilled holes could be used as drain holes, instead of just one. You could likely increase your overall flow in the process.

This would help.

 

[JumboShrimp]

Note that the ‘flaired’ ends of the returns are half-in and half-out of the water. Therefore, anytime the power to the return pump goes out (power failure / feeding mode / etc.) NO water-siphon back to the sump can occur to overflow onto the floor

 

[Danj]

I’m don’t have a PhD in Fluid Dynamics, but i am pretty sure the noise you’re getting is due to air being in the drain line. Since the durso must be vented, the line will always have air in it, and will always have some noise. Velocity would just aggravate this turbulent interface between the air and water, but practically speaking it will always be noisy at any flows we’d care about in our tanks. The only way to evacuate the air is to convert the line to a full siphon w/ a gate valve, but then you definitely want that emergency overflow line in case of snails, long term buildup, etc. I suppose one alternative to the emergency drain would be to put a leak sensor with some logic in a controller to kill your return pump if the level gets too high. That said, I am always a belt and suspenders kind of guy when it comes to matters of wife acceptance factor, and WAF would be pretty low if the place got flooded.

 

[JumboShrimp]

Don’t get discouraged or give up. I probably spent 10-15 hours reading up on different drain configurations for my bottom-drilled tank (3 holes), and everyone is of course in search of elusive “silence.” In the end, it seems unavoidable that you will have to experiment around with some holes and airline tubing— even the depth and positioning into the pipe can matter— until you find the sweet spot for your particular configuration. Just as a point of reference, I drain water from below the waterline in my overflow, and also ‘at’ the waterline; those two pipes merge together under the tank into one drain to the sump. (There is a valve that can control the ratio or ‘mix’ from the two pipes into the final single drain.) The third hole is an emergency overflow drain— hopefully never to be used— directly into the sump.

 

[Firemanreefkeeper]

I believe that a 1 inch line at full suction moves about 800 gallons per hour. The reason the durso drain has the air vent is to break the full siphon so it won't be full on 800 gallons per hour. For you with your cor20 you can run it faster and move 800 gallons but that's a lot of water. There will always be air in the line, thus the toilet flushing sound.
You can..... pull the durso part and just have a pipe in the overflow under the waterline and make your return match the water coming in. It's a very risky gamble without a gate and an emergency overflow.

 

[Heavymman]

I believe that a 1 inch line at full suction moves about 800 gallons per hour. The reason the durso drain has the air vent is to break the full siphon so it won't be full on 800 gallons per hour. For you with your cor20 you can run it faster and move 800 gallons but that's a lot of water. There will always be air in the line, thus the toilet flushing sound.
You can..... pull the durso part and just have a pipe in the overflow under the waterline and make your return match the water coming in. It's a very risky gamble without a gate and an emergency overflow.

Fortunately, my sump is sized correctly, so I wouldn’t worry about a drain clog. You don’t think adding a valve with the durso would help ? Thanks for all the help